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PLS-11: Oracle PL/SQL Reference Cursor
 
08:43
Oracle For Full Course Experience Please Go To http://mentorsnet.org/course_preview?course_id=5 Full Course Experience Includes 1. Access to course videos and exercises 2. View & manage your progress/pace 3. In-class projects and code reviews 4. Personal guidance from your Mentors
Views: 72778 Oresoft LWC
Oracle SQL Tutorial 18 - How to Create Foreign Keys
 
07:09
In this video we are going to be creating foreign keys. I highly recommend watching the previous video before you watch this one. Essentially, we are creating a very simple database for a system where we can create projects and add people to those projects. We started with the users table: --Delete the table if needed: --DROP TABLE users; CREATE TABLE users( user_id NUMBER, username VARCHAR2(50 CHAR) UNIQUE, CONSTRAINT users_pk PRIMARY KEY (user_id) ); Now we are going to create a table for projects with a column that is a foreign key to the username. We're going to want to make this match data types: CREATE TABLE projects( project_id NUMBER, project_name VARCHAR2(50 CHAR) UNIQUE, creator VARCHAR2(50 CHAR) ) Next, we need to add the column attributes we decided on last video: CREATE TABLE projects( project_id NUMBER, project_name VARCHAR2(50 CHAR) UNIQUE, creator VARCHAR2(50 CHAR) NOT NULL ) NOT NULL because we want every project to have a creator, but we are not labeling UNIQUE because that means we could only have a specific username once in the table. We want to allow a user to create multiple projects. We also need to add a primary key: CREATE TABLE projects( project_id NUMBER, project_name VARCHAR2(50 CHAR) UNIQUE, creator VARCHAR2(50 CHAR) NOT NULL, CONSTRAINT projects_pk PRIMARY KEY (username) ) Now, the question that remains is, how can I tell Oracle that I want the username to reference the username column of the other table? We have to make a foreign key constraint. As you've learned from the previous videos, there are about three ways to create constraints. You can do it inline at the column level, unnamed. You can do it at the column level, named, and you can do it at the Table level, named. Usually the table-level is preferred, but I will quickly remind you how to do all three again. CREATE TABLE projects( project_id NUMBER, project_name VARCHAR2(50 CHAR) UNIQUE, creator VARCHAR2(50 CHAR) NOT NULL REFERENCES users (username), CONSTRAINT projects_pk PRIMARY KEY (project_id) ) This works, but if we want to name it, we should do this: CREATE TABLE projects( project_id NUMBER, project_name VARCHAR2(50 CHAR) UNIQUE, creator VARCHAR2(50 CHAR) NOT NULL CONSTRAINT projects_users_fk REFERENCES users (username), CONSTRAINT projects_pk PRIMARY KEY (project_id) ) This works, but the preferred method is to do it at the table level: CREATE TABLE projects( project_id NUMBER, project_name VARCHAR2(50 CHAR) UNIQUE, creator VARCHAR2(50 CHAR) NOT NULL, CONSTRAINT projects_pk PRIMARY KEY (project_id), CONSTRAINT projects_users_fk FOREIGN KEY (creator) REFERENCES users (username) ) Great! So you've learned how to create a foreign key, now we can see it inside of Oracle SQL Developer. One important thing when it comes to foreign keys is what happens when have data in your database and you try to delete the parent row that a row in the child table references? In the next video we are going to configure that using ON DELETE. See you all then and if you enjoy this series, please do me a huge favor by liking the video and subscribing to my YouTube channel. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ HELP ME! http://www.patreon.com/calebcurry Subscribe to my newsletter: http://bit.ly/JoinCCNewsletter Donate!: http://bit.ly/DonateCTVM2. ~~~~~~~~~~~~~~~Additional Links~~~~~~~~~~~~~~~ More content: http://CalebCurry.com Facebook: http://www.facebook.com/CalebTheVideoMaker Google+: https://plus.google.com/+CalebTheVideoMaker2 Twitter: http://twitter.com/calebCurry Amazing Web Hosting - http://bit.ly/ccbluehost (The best web hosting for a cheap price!)
Views: 18616 Caleb Curry
PL/SQL tutorial 67: PL/SQL Ref Cursors In Oracle Database by Manish Sharma
 
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RebellionRider.com presents introduction to PL/SQL Ref Cursors / Cursor Variable in Oracle Database by Manish Sharma ------------------------------------------------------------------------ ►►►LINKS◄◄◄ Blog: http://bit.ly/ref-cursor-1 Previous Tutorial ►Database Cursor (Playlist): http://bit.ly/2x0JGXz ► Record Datatype (Playlist): http://bit.ly/2xkcHOr ------------------------------------------------------------------------- ►Make sure you SUBSCRIBE and be the 1st one to see my videos! ------------------------------------------------------------------------- ►►►Find me on Social Media◄◄◄ Follow What I am up to as it happens on https://twitter.com/rebellionrider http://instagram.com/rebellionrider https://plus.google.com/+Rebellionrider http://in.linkedin.com/in/mannbhardwaj/ ___Facebook Official Page of Manish Sharma___ https://www.facebook.com/TheRebellionRider/ ___Facebook Official Page of RebellionRider.com___ https://www.facebook.com/RebellionRider.official/ You can also Email me at for E-mail address please check the About section Please please LIKE and SHARE my videos it makes me happy. Thanks for liking, commenting, sharing and watching more of our videos This is Manish from RebellionRider.com ♥ I LOVE ALL MY VIEWERS AND SUBSCRIBERS
Views: 10942 Manish Sharma
Oracle Tutorial||onlinetraining||pl/sql|| Ref Cursor Part - 1  by Basha
 
33:25
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Oracle SQL Tutorial 7 - Normalization - Database Design Primer 4
 
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The database normal forms are used to normalize a database. What does it mean to normalize a database? It means to break it up into multiple tables to prevent redundant, conflicting, and bad data. The three normal forms are 1nf, 2nf, and 3nf. These stand for first normal form, second normal form, and third normal form. There are other normal forms, such as Boyce Codd normal form (BCNF), but the first 3 normal forms are the ones that are really important to know. The normal forms depend on one another. It is kind of like a ladder. In order to be in 2nd normal form, you must first be in first normal form. In order to be in 3rd normal form, you must first be in 2nd normal form. First normal form is all about individuality and giving data its space. Each column must be atomic...that is, in the smallest indivisible piece. Each value for the column must also only contain one value. To fix first normal form when you have a column violation, break the column into multiple columns. To fix first normal form when you have data violation, break the column into a new table and have a column that references the old table. Second normal form is all about partial dependencies. A partial dependency is when a column only depends on part of the primary key. This is often seen when you have an intermediary table in a many to many relationship (as a reminder, we break up many to many relationships into one to many relationships with intermediary tables in between). The solution to get rid of partial dependencies is to put the data in the table to where the column depends entirely on the key. If you do not already have a table that fits the rule, you can consider creating one. Third normal form is all about transitive dependencies. This is when a column in a table depends on another column instead of depending solely on the primary key. The solution to this is to take the column that is directly dependent on the primary key and bring it into its own table. Then, you can use foreign keys to connect the tables. This video concluded with a noble speech on how database design is very subjective. Thus is so because as we normalize more and more, the design becomes more and more complex. If we get to the point where we have hundreds of tables for a relatively small database, we can really hurt performance and increase risk of mistakes. Hopefully this video was helpful to everyone. See you in the next one! Support me: http://www.patreon.com/calebcurry Subscribe to my newsletter: http://bit.ly/JoinCCNewsletter Donate!: http://bit.ly/DonateCTVM2. ~~~~~~~~~~~~~~~Additional Links~~~~~~~~~~~~~~~ More content: http://CalebCurry.com Facebook: http://www.facebook.com/CalebTheVideoMaker Google+: https://plus.google.com/+CalebTheVideoMaker2 Twitter: http://twitter.com/calebCurry Amazing Web Hosting - http://bit.ly/ccbluehost (The best web hosting for a cheap price!)
Views: 23301 Caleb Curry
Oracle SQL Tutorial 19 - ON DELETE (SET NULL and CASCADE)
 
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Welcome everyone! Something you need to consider when you are creating foreign keys is what happens if you delete the parent? As a reminder, the parent is the row that has the value you are referencing in the row that has a foreign key. Why is this something important to consider? It's important because foreign keys need to protect us from two primary things, unacceptable INSERT statements, and unacceptable DELETE statements. Let's see what happens when we try to insert incorrect data into the table with the foreign key: INSERT INTO projects VALUES (1, 'Update website homepage', 'CalebCurry') The response tells us plainly that there is no such user in the users table. So this works correctly. Deleting data on the other hand works a bit differently because the database does not know what you want to do with the child row when you delete the parent from the parent table. By default, we will get an error message that prevents the parent from being deleted, but there are some other options. How do we configure this? This is where the ON DELETE statement comes in. We add the keywords ON DELETE right after the foreign key and then we can give it the option of CASCADE or SET NULL. CASCADE means that if we delete the parent, we are also going to delete the child. In our situation what that means is that if somebody creates a project in our project table and then that persons account gets deleted, all of the projects he owns will also be deleted. CASCADE: CREATE TABLE projects( project_id NUMBER, Project_name VARCHAR2(50 CHAR) UNIQUE, creator VARCHAR2(50 CHAR) NOT NULL, CONSTRAINT projects_pk PRIMARY KEY (project_id), CONSTRAINT projects_users_fk FOREIGN KEY (creator) REFERENCES users (username) ON DELETE CASCADE ) SET NULL will take the value in the child table and get rid of it. What you are left with is NULL. This means that we have an orphaned child. The first thought you might have is that it is a bad thing to have an orphaned child, but in databases that is not always so. In our application if we had it set to SET NULL, when a user account gets deleted the projects would remain in existence they would just lack a creator. This might be a good thing if you are concerned about the long term survival of a project, this might be the route you want to go. It ultimately depends on the application purpose. If you don't like CASCADE or SET NULL, you can leave the entire ON DELETE statement and just have Oracle throw an error when a parent is deleted. As for us, we are going to use ON DELETE CASCADE. We need to use this with extreme caution. If you are not careful, someday you will run a delete a row and that will cascade through you database deleting a bunch of stuff you didn't want to delete. Stuff happens, so make sure you back up your database every once in eternity. Now, in the last video we started with a database design that had three tables. We've only created two in this video. In the next video we are going to create the next one, which is a little special. Then we'll finish things up by adding some indexes. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Support me on Patreon! http://www.patreon.com/calebcurry Subscribe to my newsletter: http://bit.ly/JoinCCNewsletter Donate!: http://bit.ly/DonateCTVM2. ~~~~~~~~~~~~~~~Additional Links~~~~~~~~~~~~~~~ More content: http://CalebCurry.com Facebook: http://www.facebook.com/CalebTheVideoMaker Google+: https://plus.google.com/+CalebTheVideoMaker2 Twitter: http://twitter.com/calebCurry Amazing Web Hosting - http://bit.ly/ccbluehost (The best web hosting for a cheap price!)
Views: 13099 Caleb Curry
Insert and Commit: Databases for Developers #7
 
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You load data into your database tables with an insert statement. In this episode Chris discusses how to use single and multirow inserts and their pros and cons. He also covers how to persist your changes to the database with commit. See the full syntax for insert in the SQL reference guide: http://docs.oracle.com/database/122/SQLRF/INSERT.htm#SQLRF01604 Take the Databases for Developers FREE SQL course at https://devgym.oracle.com/devgym/database-for-developers.html Need help with SQL? Ask us over on AskTOM: https://asktom.oracle.com Twitter: https://twitter.com/ChrisRSaxon Daily SQL Twitter tips: https://twitter.com/SQLDaily All Things SQL blog: https://blogs.oracle.com/sql/ ============================ The Magic of SQL with Chris Saxon Copyright © 2015 Oracle and/or its affiliates. Oracle is a registered trademark of Oracle and/or its affiliates. All rights reserved. Other names may be registered trademarks of their respective owners. Oracle disclaims any warranties or representations as to the accuracy or completeness of this recording, demonstration, and/or written materials (the “Materials”). The Materials are provided “as is” without any warranty of any kind, either express or implied, including without limitation warranties or merchantability, fitness for a particular purpose, and non-infringement.
Views: 5003 The Magic of SQL
Oracle SQL Tutorial 6 - Relationships and Primary and Foreign Keys - Database Design Primer 3
 
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HAPPY VALENTINES DAY!!! Let's talk relationships.. This is the 6th video in your Oracle Database series. We are discussing database relationships which are a key feature of relational database management systems. We first discussed entities and attributes. I talked about how each entity is assigned a table and each attribute is a column within a table. We moved on to the three kinds of relationships. The first was one-to-one. This describes an entity and an attribute. A piece of data that is exclusive to an entity is, by definition, an attribute of that entity. This is stored in one table with the attribute being a column within this table. The second relationship is one-to-many. This relationship is between two entities. The way we properly store this in a database is using a foreign key in the child table. Remember, the child table is the entity on the many side of the one-to-many relationship. Every row within the child table will have a value for the foreign key that references a primary key in the parent table. This assumes that the foreign key field is not optional (NOT NULL). If the foreign key is optional, than a reference is not required but any reference must be valid. The third kind of relationship is a many-to-many relationship. In this situation, we need 3 tables. The many-to-many relationship is broken up into two one-to-many relationships. The intermediary table will associate each entity from one table with the appropriate entities in the other table. There is debate as to whether this table needs a primary key. This is because you can intact use the combination of two foreign keys as a primary key. This works because we will never have two duplicate rows within the intermediary table and the two foreign keys work as a compound key because of this. We finally discussed primary keys and foreign keys. Primary keys are used to keep each row inside of a table unique. If this key is a computer generated number it is known as a surrogate key, otherwise it is known as a natural key. Natural keys have real world meaning. For example, a social security number may work, or an email address (in some situations), etc. Whichever type of key you choose is solely up to you and/or the company you may be working for. HELP ME! http://www.patreon.com/calebcurry Subscribe to my newsletter: http://bit.ly/JoinCCNewsletter Donate!: http://bit.ly/DonateCTVM2. ~~~~~~~~~~~~~~~Additional Links~~~~~~~~~~~~~~~ More content: http://CalebCurry.com Facebook: http://www.facebook.com/CalebTheVideoMaker Google+: https://plus.google.com/+CalebTheVideoMaker2 Twitter: http://Twitter.com/calebCurry Amazing Web Hosting - http://bit.ly/ccbluehost (The best web hosting for a cheap price!)
Views: 40598 Caleb Curry
PL/SQL tutorial 26: Introduction to PL/SQL Cursor in Oracle Database By Manish Sharma
 
05:10
Learn What are cursors, what are types(Explicit and implicit), and steps of cursor's creation in oracle database by Manish Sharma From RebellionRider.com ------------------------------------------------------------------------ ►►►LINKS◄◄◄ Blog : http://bit.ly/introduction-to-database-cursors Previous Tutorial ► Pl/SQL Variables: https://youtu.be/2MNmodawvnE ------------------------------------------------------------------------- ►►►Let's Get Free Uber Cab◄◄◄ Use Referral Code UberRebellionRider and get $20 free for your first ride. ------------------------------------------------------------------------- ►Make sure you SUBSCRIBE and be the 1st one to see my videos! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ►►►Find me on Social Media◄◄◄ Follow What I am up to as it happens on https://twitter.com/rebellionrider https://www.facebook.com/imthebhardwaj http://instagram.com/rebellionrider https://plus.google.com/+Rebellionrider http://in.linkedin.com/in/mannbhardwaj/ http://rebellionrider.tumblr.com/ http://www.pinterest.com/rebellionrider/ ___Facebook Official Page___ https://www.facebook.com/RebellionRider.official/ You can also Email me at for E-mail address please check About section Please please LIKE and SHARE my videos it makes me happy. Thanks for liking, commenting, sharing and watching more of our videos This is Manish from RebellionRider.com ♥ I LOVE ALL MY VIEWERS AND SUBSCRIBERS
Views: 87759 Manish Sharma
PL/SQL: Ref Cursors
 
09:28
In this tutorial, you'll learn what is ref cursors. PL/SQL (Procedural Language/Structured Query Language) is Oracle Corporation's procedural extension for SQL and the Oracle relational database. PL/SQL is available in Oracle Database (since version 7), TimesTen in-memory database (since version 11.2.1), and IBM DB2 (since version 9.7).[1] Oracle Corporation usually extends PL/SQL functionality with each successive release of the Oracle Database. PL/SQL includes procedural language elements such as conditions and loops. It allows declaration of constants and variables, procedures and functions, types and variables of those types, and triggers. It can handle exceptions (runtime errors). Arrays are supported involving the use of PL/SQL collections. Implementations from version 8 of Oracle Database onwards have included features associated with object-orientation. One can create PL/SQL units such as procedures, functions, packages, types, and triggers, which are stored in the database for reuse by applications that use any of the Oracle Database programmatic interfaces. PL/SQL works analogously to the embedded procedural languages associated with other relational databases. For example, Sybase ASE and Microsoft SQL Server have Transact-SQL, PostgreSQL has PL/pgSQL (which emulates PL/SQL to an extent), and IBM DB2 includes SQL Procedural Language,[2] which conforms to the ISO SQL’s SQL/PSM standard. The designers of PL/SQL modeled its syntax on that of Ada. Both Ada and PL/SQL have Pascal as a common ancestor, and so PL/SQL also resembles Pascal in several aspects. However, the structure of a PL/SQL package does not resemble the basic Object Pascal program structure as implemented by a Borland Delphi or Free Pascal unit. Programmers can define public and private global data-types, constants and static variables in a PL/SQL package.[3] PL/SQL also allows for the definition of classes and instantiating these as objects in PL/SQL code. This resembles usage in object-oriented programming languages like Object Pascal, C++ and Java. PL/SQL refers to a class as an "Abstract Data Type" (ADT) or "User Defined Type" (UDT), and defines it as an Oracle SQL data-type as opposed to a PL/SQL user-defined type, allowing its use in both the Oracle SQL Engine and the Oracle PL/SQL engine. The constructor and methods of an Abstract Data Type are written in PL/SQL. The resulting Abstract Data Type can operate as an object class in PL/SQL. Such objects can also persist as column values in Oracle database tables. PL/SQL is fundamentally distinct from Transact-SQL, despite superficial similarities. Porting code from one to the other usually involves non-trivial work, not only due to the differences in the feature sets of the two languages,[4] but also due to the very significant differences in the way Oracle and SQL Server deal with concurrency and locking. There are software tools available that claim to facilitate porting including Oracle Translation Scratch Editor,[5] CEITON MSSQL/Oracle Compiler [6] and SwisSQL.[7] The StepSqlite product is a PL/SQL compiler for the popular small database SQLite. PL/SQL Program Unit A PL/SQL program unit is one of the following: PL/SQL anonymous block, procedure, function, package specification, package body, trigger, type specification, type body, library. Program units are the PL/SQL source code that is compiled, developed and ultimately executed on the database. The basic unit of a PL/SQL source program is the block, which groups together related declarations and statements. A PL/SQL block is defined by the keywords DECLARE, BEGIN, EXCEPTION, and END. These keywords divide the block into a declarative part, an executable part, and an exception-handling part. The declaration section is optional and may be used to define and initialize constants and variables. If a variable is not initialized then it defaults to NULL value. The optional exception-handling part is used to handle run time errors. Only the executable part is required. A block can have a label. Package Packages are groups of conceptually linked functions, procedures, variables, PL/SQL table and record TYPE statements, constants, cursors etc. The use of packages promotes re-use of code. Packages are composed of the package specification and an optional package body. The specification is the interface to the application; it declares the types, variables, constants, exceptions, cursors, and subprograms available. The body fully defines cursors and subprograms, and so implements the specification. Two advantages of packages are: Modular approach, encapsulation/hiding of business logic, security, performance improvement, re-usability. They support object-oriented programming features like function overloading and encapsulation. Using package variables one can declare session level (scoped) variables, since variables declared in the package specification have a session scope.
Views: 26266 radhikaravikumar
Passing by Reference, Passing by Value
 
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In this video, Steven explains the difference between passing a parameter by reference (which happens by default with IN parameters) and passing by value (which happens by default with OUT and IN OUT parameters). ====================================== Practically Perfect PL/SQL with Steven Feuerstein Copyright © 2015 Oracle and/or its affiliates. Oracle is a registered trademark of Oracle and/or its affiliates. All rights reserved. Other names may be registered trademarks of their respective owners. Oracle disclaims any warranties or representations as to the accuracy or completeness of this recording, demonstration, and/or written materials (the “Materials”). The Materials are provided “as is” without any warranty of any kind, either express or implied, including without limitation warranties or merchantability, fitness for a particular purpose, and non-infringement.
Oracle Tutorials | Primary key & Foreign Key Reference key Relationship in Oracle | by Mr.Sudhakar L
 
13:36
Oracle Tutorials | Primary key & Foreign Key Reference key Relationship in Oracle | by Mr.Sudhakar L ** For Online Training Registration: https://goo.gl/r6kJbB ► Call: +91-8179191999 #OracleTutorials | #Primary_key_ForeignKeyReference ► Visit Our Website for Classroom Training: https://nareshit.in ► For Online Training: https://nareshit.com/ -------------------------- ► About NareshIT: "Naresh IT is having 14+ years of experience in software training industry and the best Software Training Institute for online training, classroom training, weekend training, corporate training of Hadoop, Salesforce, AWS, DevOps, Spark, Data Science, Python, Tableau, RPA ,Java, C#.NET, ASP.NET, Oracle, Testing Tools, Silver light, Linq, SQL Server, Selenium, Android, iPhone, C Language, C++, PHP and Digital Marketing in USA,Hyderabad, Chennai and Vijayawada,Bangalore India which provides online training across all the locations -------------------------- ► Our Online Training Features: 1.Training with Real-Time Experts 2.Industry Specific Scenario’s 3.Flexible Timings 4.Soft Copy of Material 5. Share Videos of each and every session. -------------------------- Please write back to us at [email protected]/[email protected] or Call us at USA: +1404-232-9879 or India: +918179191999 ** Check The Below Links** ► For Course Reg: https://goo.gl/r6kJbB ► Subscribe to Our Channel: https://goo.gl/q9ozyG ► Circle us on G+: https://plus.google.com/NareshIT ► Like us on Facebook: https://www.facebook.com/NareshIT ► Follow us on Twitter: https://twitter.com/nareshitech ► Follow us on Linkedin: https://in.linkedin.com/company/naresh-i-technologies ► Follow us on Instagram: https://www.instagram.com/nareshitech/
SQL tutorials 18: SQL Foreign Key Constraint
 
10:23
SQL Tutorial 18: SQL foreign key constraint. Topic covered in this tutorial 1. Defining SQL foreign key using create table at column level 2. Defining SQL foreign key using create table at table level 1. Defining SQL foreign key using Alter Table statement Links Website article: http://www.rebellionrider.com/sql-foreign-key.htm Primary key tutorial: http://www.rebellionrider.com/sql-foreign-key.htm Create Table Tutorial: http://www.rebellionrider.com/sql-create-table.html Tool used in this tutorial is SQL Developer. This tutorial series is part of SQL expert exam certification training. if you are preparing for SQL certification you can use my tutorials. This SQL Tutorial is a part of free training. Copy Cloud referral link || Use this link to join copy cloud and get 20GB of free storage https://copy.com?r=j7eYO7 Contacts E-Mail [email protected] Twitter https://twitter.com/rebellionrider Instagram http://instagram.com/rebellionrider Facebook. https://www.facebook.com/imthebhardwaj Linkedin. http://in.linkedin.com/in/mannbhardwaj/ Thanks for linking, commenting, sharing and watching more of our videos This is Manish from RebellionRider.com Foreign key is an Input/output data constraint which is also known as referential integrity constraint. Foreign key represent a link or say a relationship between columns of tables. Similar to primary key constraint Foreign Key constraint is also of two types. Simple Foreign key constraint and Composite Foreign key constraint. Constraint which involves only one column in foreign key in child table and one column in reference key in parent table is called Simple Foreign Key. While the constraint which involves more than one column in foreign key in child table and more than one column in reference key in the parent table is called Composite Foreign Key.
Views: 98860 Manish Sharma
REF CURSOR AND SYS_REFCURSOR IN ORACLE PL/SQL WITH EXAMPLE
 
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This video explains about ref cursor in oracle pl/sql, what are ref cursors, how are ref cursor different from simple cursors, what are the advantages of using a ref cursor etc. The video demonstrates proper and easy to understand examples on ref cursor.
Views: 8700 Kishan Mashru
PL/SQL: Object Type
 
08:31
In this tutorial, you'll learn what is a object type in sql/plsql PL/SQL (Procedural Language/Structured Query Language) is Oracle Corporation's procedural extension for SQL and the Oracle relational database. PL/SQL is available in Oracle Database (since version 7), TimesTen in-memory database (since version 11.2.1), and IBM DB2 (since version 9.7).[1] Oracle Corporation usually extends PL/SQL functionality with each successive release of the Oracle Database. PL/SQL includes procedural language elements such as conditions and loops. It allows declaration of constants and variables, procedures and functions, types and variables of those types, and triggers. It can handle exceptions (runtime errors). Arrays are supported involving the use of PL/SQL collections. Implementations from version 8 of Oracle Database onwards have included features associated with object-orientation. One can create PL/SQL units such as procedures, functions, packages, types, and triggers, which are stored in the database for reuse by applications that use any of the Oracle Database programmatic interfaces. PL/SQL works analogously to the embedded procedural languages associated with other relational databases. For example, Sybase ASE and Microsoft SQL Server have Transact-SQL, PostgreSQL has PL/pgSQL (which emulates PL/SQL to an extent), and IBM DB2 includes SQL Procedural Language,[2] which conforms to the ISO SQL’s SQL/PSM standard. The designers of PL/SQL modeled its syntax on that of Ada. Both Ada and PL/SQL have Pascal as a common ancestor, and so PL/SQL also resembles Pascal in several aspects. However, the structure of a PL/SQL package does not resemble the basic Object Pascal program structure as implemented by a Borland Delphi or Free Pascal unit. Programmers can define public and private global data-types, constants and static variables in a PL/SQL package.[3] PL/SQL also allows for the definition of classes and instantiating these as objects in PL/SQL code. This resembles usage in object-oriented programming languages like Object Pascal, C++ and Java. PL/SQL refers to a class as an "Abstract Data Type" (ADT) or "User Defined Type" (UDT), and defines it as an Oracle SQL data-type as opposed to a PL/SQL user-defined type, allowing its use in both the Oracle SQL Engine and the Oracle PL/SQL engine. The constructor and methods of an Abstract Data Type are written in PL/SQL. The resulting Abstract Data Type can operate as an object class in PL/SQL. Such objects can also persist as column values in Oracle database tables. PL/SQL is fundamentally distinct from Transact-SQL, despite superficial similarities. Porting code from one to the other usually involves non-trivial work, not only due to the differences in the feature sets of the two languages,[4] but also due to the very significant differences in the way Oracle and SQL Server deal with concurrency and locking. There are software tools available that claim to facilitate porting including Oracle Translation Scratch Editor,[5] CEITON MSSQL/Oracle Compiler [6] and SwisSQL.[7] The StepSqlite product is a PL/SQL compiler for the popular small database SQLite. PL/SQL Program Unit A PL/SQL program unit is one of the following: PL/SQL anonymous block, procedure, function, package specification, package body, trigger, type specification, type body, library. Program units are the PL/SQL source code that is compiled, developed and ultimately executed on the database. The basic unit of a PL/SQL source program is the block, which groups together related declarations and statements. A PL/SQL block is defined by the keywords DECLARE, BEGIN, EXCEPTION, and END. These keywords divide the block into a declarative part, an executable part, and an exception-handling part. The declaration section is optional and may be used to define and initialize constants and variables. If a variable is not initialized then it defaults to NULL value. The optional exception-handling part is used to handle run time errors. Only the executable part is required. A block can have a label. Package Packages are groups of conceptually linked functions, procedures, variables, PL/SQL table and record TYPE statements, constants, cursors etc. The use of packages promotes re-use of code. Packages are composed of the package specification and an optional package body. The specification is the interface to the application; it declares the types, variables, constants, exceptions, cursors, and subprograms available. The body fully defines cursors and subprograms, and so implements the specification. Two advantages of packages are: Modular approach, encapsulation/hiding of business logic, security, performance improvement, re-usability. They support object-oriented programming features like function overloading and encapsulation. Using package variables one can declare session level (scoped) variables, since variables declared in the package specification have a session scope.
Views: 12056 radhikaravikumar
SQL: Foreign Key Creation
 
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In this tutorial, you'll learn how to create a foreign key column ....
Views: 37824 radhikaravikumar
Oracle Database 12c: Better PL/SQL From SQL
 
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Overview and demonstration of using the plsql_declarations clause to embed a PL/SQL function in a SQL SELECT statement. "plsql_declarations" in Oracle® Database SQL Language Reference http://www.oracle.com/pls/topic/lookup?ctx=db121&id=BABJCBCC
Views: 2574 OracleDBVision
Top 50 SQL Interview Questions and Answers Part 1
 
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Best Buy Links (affiliate): SQL The Complete Reference https://amzn.to/2NAfr2G SQL Cookbook (Covers SQL Server, PostgrSQL, Oracle, MySQL, And Db2) https://amzn.to/2MhU6Xl Beginning SQL Queries https://amzn.to/2NzaAPj SQL, PL/SQL the Programming Language of Oracle https://amzn.to/2QjIyWH SQL in easy steps https://amzn.to/2x73t6G T-SQL Fundamentals https://amzn.to/2NywZfC Microsoft SQL Server 2012 Step By Step https://amzn.to/2O8BMBI ----------------------------------- SQL INTERVIEW QUESTIONS AND ANSWERS on this link - https://viden.io/knowledge/sql-interview-questions-and-answers DBMS notes-https://viden.io/knowledge/dbms-interview-q-a
Views: 307465 LearnEveryone
PL/SQL Oracle REF CURSOR and SYS_REFCURSOR tutorial
 
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REF CURSOR declaration is not associated with any SQL query - different queries can be associated with the cursor programatically. More video tutorials http://www.learn-with-video-tutorials.com
SQL Foreign Key Constraints
 
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Jamie King of Neumont University showing what are and how to add foreign key constraints.
Views: 51929 Jamie King
Oracle SQL Tutorial 22 - Why Primary Keys Shouldn't Change
 
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In the last video I mentioned that with our database design it is important to make sure that nobody tries to update a user's username. What happens if they do? Nothing horrible, Oracle will just throw an error. That's not such a big deal, but if you are hoping to make some kind of application that allows someone to change their username, this is not the best set up. Why? If you look at the projects table, we have a foreign key that references the username. Let's assume for a moment that Oracle allows you to do anything with your data. That means that if a user updates their username, there will be projects created by users that don't exist. Or a user could change their name to the previous owner. To fix this problem, we would need something such as an ON UPDATE CASCADE command for our foreign key. That would mean that if the user updated their username, the columns that reference that username would also update to the new value. This exists in some database management systems, but this does not exist in Oracle at the time of this video. How do we get around this problem? I'm sure we could conjure up something to allow us to update the username, but the easiest solution is to reference the user_id instead of the username. That way, when the username is updated, nothing changes inside of the foreign key. As a general rule, primary keys should never change. Foreign keys CAN change, but they should not change because a primary key changed. So, if we did happen to use a username as a column, it would be frowned upon if the username had to change because the column it references changes. However, it would be acceptable to change the foreign key if we needed to point to a new entity in the users table. Even if a username is never intended to change, these complications bother a lot of people. You can mitigate these problems by only referencing surrogate keys in foreign keys. This has the downside though that when you retrieve the data, you are going to have to do more work to make the data readable. For example, we had a table that was called project_users. It is essentially a table that says what users are part of what projects. We could have the foreign keys reference the project's name and the user's username. Then when you could say SELECT * FROM project_users. The data would be completely readable without doing anything. If you switch to only referencing surrogate primary keys, you will have a bunch of random numbers that don't mean anything and will have to be joined with other tables…which is really super frustrating when later you have to join a thousand tables to read anything. Which side do you prefer? Pick a side. Choose wisely. I'll see you all in the next video ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ HELP ME! http://www.patreon.com/calebcurry Subscribe to my newsletter: http://bit.ly/JoinCCNewsletter Donate!: http://bit.ly/DonateCTVM2. ~~~~~~~~~~~~~~~Additional Links~~~~~~~~~~~~~~~ More content: http://CalebCurry.com Facebook: http://www.facebook.com/CalebTheVideoMaker Google+: https://plus.google.com/+CalebTheVideoMaker2 Twitter: http://twitter.com/calebCurry Amazing Web Hosting - http://bit.ly/ccbluehost (The best web hosting for a cheap price!)
Views: 5087 Caleb Curry
PL/SQL tutorial 6: Bind Variable in PL/SQL By Manish Sharma RebellionRider.com
 
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Watch and learn what are bind variables in PL/SQL how to declare or create them using Variable command, Initialize them using Execute (exec)command and different ways of displaying current values of a bind variable for example using AutoPrint parameter. ------------------------------------------------------------------------ ►►►LINKS◄◄◄ Blog : http://bit.ly/bind-variable Previous Tutorial ► Constants in PL/SQL https://youtu.be/r1ypg7WH4GY ►User Variables :https://youtu.be/2MNmodawvnE ------------------------------------------------------------------------- ►►►Let's Get Free Uber Cab◄◄◄ Use Referral Code UberRebellionRider and get $20 free for your first ride. ------------------------------------------------------------------------- ►►►Help Me In Getting A Job◄◄◄ ►Help Me In Getting A Good Job By Connecting With Me on My LinkedIn and Endorsing My Skills. All My Contact Info is Down Below. You Can Also Refer Me To Your Company Thanks ------------------------------------------------------------------------- ►Make sure you SUBSCRIBE and be the 1st one to see my videos! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ►►►Find me on Social Media◄◄◄ Follow What I am up to as it happens on https://twitter.com/rebellionrider https://www.facebook.com/imthebhardwaj http://instagram.com/rebellionrider https://plus.google.com/+Rebellionrider http://in.linkedin.com/in/mannbhardwaj/ http://rebellionrider.tumblr.com/ http://www.pinterest.com/rebellionrider/ You can also Email me at for E-mail address please check About section Please please LIKE and SHARE my videos it makes me happy. Thanks for liking, commenting, sharing and watching more of our videos This is Manish from RebellionRider.com ♥ I LOVE ALL MY VIEWERS AND SUBSCRIBERS
Views: 84637 Manish Sharma
Foreign Key | Database Management System
 
06:29
To ask your doubts on this topic and much more, click on this Direct Link: http://www.techtud.com/video-lecture/lecture-foreign-key IMPORTANT LINKS: 1) Official Website: http://www.techtud.com/ 2) Virtual GATE: http://virtualgate.in/login/index.php Both of the above mentioned platforms are COMPLETELY FREE, so feel free to Explore, Learn, Practice & Share! Our Social Media Links: Facebook Page: https://www.facebook.com/techtuduniversity Facebook Group: https://www.facebook.com/groups/virtualgate Google+ Page: https://plus.google.com/+techtud/posts Last but not the least, SUBSCRIBE our YouTube channel to stay updated about the regularly uploaded new videos.
Views: 243222 Techtud
Oracle SQL Tutorial 16 - Parent Child Relationships
 
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So far in this series we have discussed database design, creating tables, and constraints. We've brought up the concept of foreign keys, but we have not explained how to create them. That is the goal of this video and the upcoming videos. We want to study those foreign keys! Let's make them not so foreign. Let's learn the proper way to define a foreign key. As a reminder, a foreign key is a column that references a column of another table. The column it references must either be a primary key, or have the UNIQUE constraint. This means that every value inside of the column that is labeled as a foreign key, there must be that value in some row of the referenced column. As an example, imagine that we have the users table, and we have a table service_requests. We could have a column in the service_request that references a column in the users table. Usually this would be the primary key that is referenced, but there is nothing stopping you from referencing a unique column. Just for fun, let's go through an example using the username column. If we have a service_requests table, every single row within the table is going to be what some would consider an instance of a service_request. This means that the table columns are like the blueprint for what a service request looks like and then each row is an individual service request. If we have one of the columns labeled as a foreign key to the username of the users table, what does that mean practically? It means that for a single row, the value for that column must be a value that exists in the users table. We could have a service_request submitted by a user with the username of Yoloswagman. This means that there must be a row inside of the users table that has the value Yoloswagman for the username column. This brings up the concept of parent and child relationships. Yoloswagman in this situation is the parent, and his service request is the child. When we draw it out, it makes sense why a primary key must be UNIQUE. If we had two Yoloswagmans, the child would not know which column is the parent. The same applies if we were using IDs and we had So remember, always reference a primary key or a column with the UNIQUE constraint. Now, I have a question for you. Do foreign keys automatically have the UNIQUE constraint, just like primary keys? The answer is no. A parent row can have many child rows. It makes sense because the user could submit multiple service requests. Can we force the column to be unique? Absolutely. If that was the case, the user could only make one service request. Another question. Do foreign keys automatically have the NOT NULL constraint, just like primary keys? The answer is no. Essentially what this means is that a child could be created with no parent. Can we force the column to be NOT NULL? Absolutely. It is ok in some situations to allow the row to be null, but in this situation it makes no sense. It would be wise for us to add that constraint ourselves. So now that you understand some more differences between primary and foreign keys and parent child relationships, take all of these questions into consideration when you are creating foreign keys. In the next video, we are going to start a small project that is going to require multiple tables. We'll take a video to design our structure and then we'll get to creating those foreign keys in Oracle SQL Developer. Stick around and if you like these videos please be a serious supporter and subscribe to my channel. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ HELP ME! http://www.patreon.com/calebcurry Subscribe to my newsletter: http://bit.ly/JoinCCNewsletter Donate!: http://bit.ly/DonateCTVM2. ~~~~~~~~~~~~~~~Additional Links~~~~~~~~~~~~~~~ More content: http://CalebCurry.com Facebook: http://www.facebook.com/CalebTheVideoMaker Google+: https://plus.google.com/+CalebTheVideoMaker2 Twitter: http://twitter.com/calebCurry Amazing Web Hosting - http://bit.ly/ccbluehost (The best web hosting for a cheap price!)
Views: 10730 Caleb Curry
PL/SQL tutorial 68: PL/SQL Strong Ref Cursor in Oracle Database
 
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RebellionRider.com presents the second tutorial in PL/SQL Ref Cursors series explaining the concepts of Strong Ref Cursors in Oracle Database by Manish Sharma. ------------------------------------------------------------------------ ►►►LINKS◄◄◄ Blog: http://bit.ly/ref-cursor-2 Previous Tutorial ► Record Datatypes: https://youtu.be/8WqpqKUj9l8 ► Database Cursors: https://youtu.be/_snAMqCBitg ------------------------------------------------------------------------- ►Make sure you SUBSCRIBE and be the 1st one to see my videos! ------------------------------------------------------------------------- ►►►Find me on Social Media◄◄◄ Follow What I am up to as it happens on https://twitter.com/rebellionrider http://instagram.com/rebellionrider https://plus.google.com/+Rebellionrider http://in.linkedin.com/in/mannbhardwaj/ ___Facebook Official Page of Manish Sharma___ https://www.facebook.com/TheRebellionRider/ ___Facebook Official Page of RebellionRider.com___ https://www.facebook.com/RebellionRider.official/ You can also Email me at for E-mail address please check the About section Please please LIKE and SHARE my videos it makes me happy. Thanks for liking, commenting, sharing and watching more of our videos This is Manish from RebellionRider.com ♥ I LOVE ALL MY VIEWERS AND SUBSCRIBERS
Views: 7681 Manish Sharma
PL/SQL tutorial 30: Cursor FOR Loop In Oracle Database By Manish Sharma
 
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Learn How To Work with Database (Explicit or Implicit) Cursors using Cursor For Loop in Oracle Database With Example By Manish Sharma on RebellionRider.com ------------------------------------------------------------------------ ►►►LINKS◄◄◄ Blog : http://bit.ly/cursor-for-loop-1 Previous Tutorial ► Numeric For Loop: https://youtu.be/DfAmnj2j7WI ►Install SQL Developer: https://youtu.be/zliF8kXVmeE ------------------------------------------------------------------------- ►►►Let's Get Free Uber Cab◄◄◄ Use Referral Code UberRebellionRider and get $20 free for your first ride. ------------------------------------------------------------------------- ►Make sure you SUBSCRIBE and be the 1st one to see my videos! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ►►►Find me on Social Media◄◄◄ Follow What I am up to as it happens on https://twitter.com/rebellionrider https://www.facebook.com/imthebhardwaj http://instagram.com/rebellionrider https://plus.google.com/+Rebellionrider http://in.linkedin.com/in/mannbhardwaj/ http://rebellionrider.tumblr.com/ http://www.pinterest.com/rebellionrider/ ___Facebook Official Page___ https://www.facebook.com/RebellionRider.official/ You can also Email me at for E-mail address please check About section Please please LIKE and SHARE my videos it makes me happy. Thanks for liking, commenting, sharing and watching more of our videos This is Manish from RebellionRider.com ♥ I LOVE ALL MY VIEWERS AND SUBSCRIBERS
Views: 35209 Manish Sharma
Explaining the Explain Plan: Interpreting Execution Plans for SQL Statements
 
01:04:02
Presenter: Maria Colgan, Oracle Corporation The execution plan for a SQL statement can often seem complicated and hard to understand. Determining if the execution plan you are looking at is the best plan you could get or attempting to improve a poorly performing execution plan can be a daunting task, even for the most experienced DBA or developer. This session examines the different aspects of an execution plan, from selectivity to parallel execution, and explains what information you should be gleaming from the plan and how it affects the execution. It offers insight into what caused the Optimizer to make the decision it did as well as a set of corrective measures that can be used to improve each aspect of the plan.
Views: 3313 ODTUG
Using Cursor in Oracle PL SQL
 
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Using Cursor in Oracle PL SQL By Dr. RD Balaji Help us caption & translate this video! http://amara.org/v/DWUs/
77. Introduction to Cursor in PL/SQL Oracle
 
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In this video you will learn about Introduction to Cursor in PL/SQL Oracle. For Support =========== Email: [email protected] Contact Form: http://www.learninhindi.com/home/contact Our Social Media ================ Facebook: https://www.facebook.com/LearnInHindi Twitter: https://twitter.com/LearnInHindi For Training & Videos ===================== For more videos and articles visit: http://www.learninhindi.com Free Java Programming In Hindi Course ===================================== https://www.youtube.com/playlist?list=PLOZ3jentlCDAwwhMyoLISrxkXTADGp7PH Free Oracle PL/SQL Programming In Hindi Course ============================================== https://www.youtube.com/playlist?list=PLB5DA82419C2D99B6 Free C Programming In Hindi Course ================================== https://www.youtube.com/playlist?list=PLOZ3jentlCDAxKpBLMWogxSdy6BZcsAJq Trips & Tricks Channel ====================== https://www.youtube.com/channel/UCGmLfkuCo-3lHHJXRJ9HUMw Programming in Hindi Channel ============================ https://www.youtube.com/channel/UCudElIDgwNrybeAvXIy1HZQ
Views: 9647 ITORIAN
PL/SQL: Ref cursor Types
 
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In this tutorial, you'll learn the types of ref cursors.. PL/SQL (Procedural Language/Structured Query Language) is Oracle Corporation's procedural extension for SQL and the Oracle relational database. PL/SQL is available in Oracle Database (since version 7), TimesTen in-memory database (since version 11.2.1), and IBM DB2 (since version 9.7).[1] Oracle Corporation usually extends PL/SQL functionality with each successive release of the Oracle Database. PL/SQL includes procedural language elements such as conditions and loops. It allows declaration of constants and variables, procedures and functions, types and variables of those types, and triggers. It can handle exceptions (runtime errors). Arrays are supported involving the use of PL/SQL collections. Implementations from version 8 of Oracle Database onwards have included features associated with object-orientation. One can create PL/SQL units such as procedures, functions, packages, types, and triggers, which are stored in the database for reuse by applications that use any of the Oracle Database programmatic interfaces. PL/SQL works analogously to the embedded procedural languages associated with other relational databases. For example, Sybase ASE and Microsoft SQL Server have Transact-SQL, PostgreSQL has PL/pgSQL (which emulates PL/SQL to an extent), and IBM DB2 includes SQL Procedural Language,[2] which conforms to the ISO SQL’s SQL/PSM standard. The designers of PL/SQL modeled its syntax on that of Ada. Both Ada and PL/SQL have Pascal as a common ancestor, and so PL/SQL also resembles Pascal in several aspects. However, the structure of a PL/SQL package does not resemble the basic Object Pascal program structure as implemented by a Borland Delphi or Free Pascal unit. Programmers can define public and private global data-types, constants and static variables in a PL/SQL package.[3] PL/SQL also allows for the definition of classes and instantiating these as objects in PL/SQL code. This resembles usage in object-oriented programming languages like Object Pascal, C++ and Java. PL/SQL refers to a class as an "Abstract Data Type" (ADT) or "User Defined Type" (UDT), and defines it as an Oracle SQL data-type as opposed to a PL/SQL user-defined type, allowing its use in both the Oracle SQL Engine and the Oracle PL/SQL engine. The constructor and methods of an Abstract Data Type are written in PL/SQL. The resulting Abstract Data Type can operate as an object class in PL/SQL. Such objects can also persist as column values in Oracle database tables. PL/SQL is fundamentally distinct from Transact-SQL, despite superficial similarities. Porting code from one to the other usually involves non-trivial work, not only due to the differences in the feature sets of the two languages,[4] but also due to the very significant differences in the way Oracle and SQL Server deal with concurrency and locking. There are software tools available that claim to facilitate porting including Oracle Translation Scratch Editor,[5] CEITON MSSQL/Oracle Compiler [6] and SwisSQL.[7] The StepSqlite product is a PL/SQL compiler for the popular small database SQLite. PL/SQL Program Unit A PL/SQL program unit is one of the following: PL/SQL anonymous block, procedure, function, package specification, package body, trigger, type specification, type body, library. Program units are the PL/SQL source code that is compiled, developed and ultimately executed on the database. The basic unit of a PL/SQL source program is the block, which groups together related declarations and statements. A PL/SQL block is defined by the keywords DECLARE, BEGIN, EXCEPTION, and END. These keywords divide the block into a declarative part, an executable part, and an exception-handling part. The declaration section is optional and may be used to define and initialize constants and variables. If a variable is not initialized then it defaults to NULL value. The optional exception-handling part is used to handle run time errors. Only the executable part is required. A block can have a label. Package Packages are groups of conceptually linked functions, procedures, variables, PL/SQL table and record TYPE statements, constants, cursors etc. The use of packages promotes re-use of code. Packages are composed of the package specification and an optional package body. The specification is the interface to the application; it declares the types, variables, constants, exceptions, cursors, and subprograms available. The body fully defines cursors and subprograms, and so implements the specification. Two advantages of packages are: Modular approach, encapsulation/hiding of business logic, security, performance improvement, re-usability. They support object-oriented programming features like function overloading and encapsulation. Using package variables one can declare session level (scoped) variables, since variables declared in the package specification have a session scope.
Views: 11908 radhikaravikumar
PL/SQL Tutorial  4 :  PLSQL Procedures %Type, %ROWTYPE & NOCOPY
 
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PLSQL Tutorial For Beginners 4 : PLSQL Procedures %Type, %ROWTYPE & NOCOPY SQL Tutorial SQL Tutorial for beginners PLSQL Tutorial PLSQL Tutorial for beginners PL/SQL Tutorial PL/SQL Tutorial for beginners Oracle SQL Tutorial
Views: 693 TechLake
PLS-4: PL/SQL Variables
 
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For Full Course Experience Please Go To http://mentorsnet.org/course_preview?course_id=5 Full Course Experience Includes 1. Access to course videos and exercises 2. View & manage your progress/pace 3. In-class projects and code reviews 4. Personal guidance from your Mentors ---------------------------------------------------------------------------------------- A variable is nothing but a name given to a storage area that our programs can manipulate. Each variable in PL/SQL has a specific data type, which determines the size and layout of the variable's memory; the range of values that can be stored within that memory and the set of operations that can be applied to the variable. The name of a PL/SQL variable consists of a letter optionally followed by more letters, numerals, dollar signs, underscores, and number signs and should not exceed 30 characters. By default, variable names are not case-sensitive. You cannot use a reserved PL/SQL keyword as a variable name. PL/SQL programming language allows to define various types of variables, which we will cover in subsequent chapters like date time data types, records, collections, etc. For this chapter, let us study only basic variable types. With PL/SQL you can declare variables and then use them in SQL and procedural statements anywhere that an expression can be used. Variables can be used for the following: • Temporary storage of data: Data can be temporarily stored in one or more variables for use when validating data input and for processing later in the data flow process. • Manipulation of stored values: Variables can be used for calculations and other data manipulations without accessing the database. • Reusability: After they are declared, variables can be used repeatedly in an application simply by referencing them in other statements, including other declarative statements. • Ease of maintenance: When using %TYPE and %ROWTYPE (more information on %ROWTYPE is covered in a subsequent lesson), you declare variables, basing the declarations on the definitions of database columns. If an underlying definition changes, the variable declaration changes accordingly at run time. This provides data independence, reduces maintenance costs, and allows programs to adapt as the database changes to meet new business needs. More information on %TYPE is covered later in this lesson. Types of Variables" All PL/SQL variables have a data type, which specifies a storage format, constraints, and valid range of values. PL/SQL supports four data type categories—scalar, composite, reference, and LOB (large object)—that you can use for declaring variables, constants, and pointers. • Scalar data types hold a single value. The main data types are those that correspond to column types in Oracle server tables; PL/SQL also supports Boolean variables. • Composite data types, such as records, allow groups of fields to be defined and manipulated in PL/SQL blocks. • Reference data types hold values, called pointers, that designate other program items. Reference data types are not covered in this course. • LOB data types hold values, called locators, that specify the location of large objects (such as graphic images) that are stored out of line. LOB data types are discussed in detail later in this course.
Views: 41401 Oresoft LWC
Download Oracle SQL Tuning Pocket Reference PDF
 
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http://j.mp/1T7B7PL
Views: 3 Lois Bourgeois
ORACLE SQL- 8. double ampersand
 
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insead of repeating the same value always we can make it as a fixed value using double ampersand
Views: 924 Ban3 GaiN
Oracle SQL Tutorial 21 - How to Create / Drop Indexes
 
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In the last video, we wrote up the SQL to create three tables: CREATE TABLE users( user_id NUMBER, username VARCHAR2(50 CHAR) UNIQUE, CONSTRAINT users_pk PRIMARY KEY (user_id) ); CREATE TABLE projects( project_id NUMBER, Project_name VARCHAR2(50 CHAR) UNIQUE, creator VARCHAR2(50 CHAR) NOT NULL, CONSTRAINT projects_pk PRIMARY KEY (project_id), CONSTRAINT projects_users_fk FOREIGN KEY (creator) REFERENCES users (username) ON DELETE CASCADE ); CREATE TABLE project_users( project_id NUMBER NOT NULL REFERENCES projects (project_id) ON DELETE CASCADE, user_id NUMBER NOT NULL REFERENCES users (user_id) ON DELETE CASCADE, CONSTRAINT project_users_pk PRIMARY KEY (project_id, user_id) ); I'm going to increase the size of the users table a bit by adding a first and last name column. CREATE TABLE users( user_id NUMBER, username VARCHAR2(50 CHAR) UNIQUE, first_name VARCHAR2(50 CHAR), last_name VARCHAR2 (50 CHAR), CONSTRAINT users_pk PRIMARY KEY (user_id) ); But before we finish this design, we should consider indexing certain columns. What columns should we index? Well, as a reminder, the columns that are indexed by default are columns with the UNIQUE constraint, and those that are labeled as primary keys. Columns that are not indexed but often should be are those labeled as a foreign key. The column that jumps out the most to me is the creator column of the project table. It's the only foreign key that is not part of some index. Let's fix this by creating our first index. The way we do that is with the CREATE INDEX command. CREATE INDEX projects_creator_ix ON projects (creator) What naming convention are we following for the index? We are naming it by the table name, followed by an underscore, followed by the column, followed by an underscore, followed by an ix (for index). In this situation it does not apply, but if our foreign key column is labeled as UNIQUE, we can add the UNIQUE keyword like this: CREATE UNIQUE INDEX projects_creator_ix ON projects (creator) Now if you want to get rid of an INDEX, you can use this command: DROP INDEX projects_creator_ix Now, if we want to select data from the user table and the project table we can do that much faster. That's because the foreign key and column it references are both indexed and those are the columns we would do the join on. We will discuss how to do joins in a future video. So what are some potential problems with this database design? Overall, it is pretty good. With this design though we need to make sure there is no way for someone to update a user's username. In the next video we are going to discuss why. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Support me on Patreon! http://www.patreon.com/calebcurry Subscribe to my newsletter: http://bit.ly/JoinCCNewsletter Donate!: http://bit.ly/DonateCTVM2. ~~~~~~~~~~~~~~~Additional Links~~~~~~~~~~~~~~~ More content: http://CalebCurry.com Facebook: http://www.facebook.com/CalebTheVideoMaker Google+: https://plus.google.com/+CalebTheVideoMaker2 Twitter: http://twitter.com/calebCurry Amazing Web Hosting - http://bit.ly/ccbluehost (The best web hosting for a cheap price!)
Views: 7523 Caleb Curry
SelectTec | Aula Nº 31 | Continuação Foreign Key - Oracle SQL Developer
 
10:30
Syntax: ALTER TABLE table_name ADD CONSTRAINT constraint_name FOREIGN KEY (column1, column2, ... column_n) REFERENCES parent_table (column1, column2, ... column_n);
Views: 1361 SelectTec
How to Join 3 tables in 1 SQL query
 
04:59
Get your first month on the Joes 2 Pros Academy for just $1 with code YOUTUBE1. Visit http://www.joes2pros.com Offer expires July 1, 2015 From the newly released 2 Disc DVD set (SQL Queries Joes 2 Pros Vol2) this video shows how to join 3 tables in 1 query.
Views: 244018 Joes2Pros SQL Trainings
Oracle SQL Performance Tuning
 
07:40
A beginner's guide that shows you how to start on SQL Performance tuning with reference to Oracle. Talks about plans, indexes and hints. Visit the associated web page at http://blog.hardeep.name/computer/20090217/sql-tuning/ For those unable to understand the accent, or looking for a more advanced tutorial visit http://blog.hardeep.name/general/20090711/app-tuning/
Views: 55480 dwealth
Oracle Database 12c: Improved Defaults
 
05:59
Tom Kyte and Chuck Murray describe several improvements to default behavior in Oracle Database 12c: defaults based on sequences, default on NULL, Identity type columns, and metadata-only defaults. For more information: "CREATE TABLE" statement in Oracle® Database SQL Language Reference http://www.oracle.com/pls/topic/lookup?ctx=db121&id=SQLRF01402 "ALTER TABLE" statement in Oracle® Database SQL Language Reference http://www.oracle.com/pls/topic/lookup?ctx=db121&id=SQLRF01001 "Identity Columns" in Oracle® Database Migration Guide http://www.oracle.com/pls/topic/lookup?ctx=db121&id=DRDAA109
Views: 2063 OracleDBVision

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