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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: 14147 Caleb Curry
SQL tutorials 20: On Delete Cascade Foreign Key By Manish Sharma (RebellionRider)
 
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Oracle Database 11g Tutorial 20: On delete cascade This tutorial will show you how to define foreign key with on delete cascade clause. Links Blog: http://www.rebellionrider.com/on-delete-cascade.htm SQL Tutorial 19 On delete set Null: http://www.rebellionrider.com/on-delete-cascade.htm SQL Tutorial 19 Foreign Key: http://youtu.be/0nbkBI5r3Gw Copy Cloud referral link || Use this link to join copy cloud and get 20GB of free storage https://copy.com?r=j7eYO7 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. 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 liking, commenting, sharing and watching more of our videos This is Manish from RebellionRider.com
Views: 44421 Manish Sharma
Oracle Drop, Disable and Enable Constraints تعليم اوراكل
 
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by Mohamed El Desouki - محمد الدسوقى [email protected] Tel :00966 553450836 جامعة سلمان بن عبد العزيز - السعودية - الخرج How to Drop , Disable and Enable Constraints. كيف حذف و تعطيل و إعادة تشغيل القيود Text Book: Fundamentals of Database Systems, 5th Edition, by Elmasri/Navathe, published by Addison-W oracle create table statement oracle drop table statement oracle constraints database constraints primary key constraint foreign key constraint check constraint null not null constraint unique constraint
How to drop tablespace in Oracle 10g or 11g
 
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This is how to drop tablespace in oracle 10g or oracle 11g, you can delete tablespace in oracle if you want. Delete or drop tablesapce in oracle cascade
Views: 231 Tanya Kenapa?
SQL tutorial 40: DBA Trick, How to drop a user when it is connected to the database
 
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Watch in HD,Dropping a user is easy only when it is not connected to the database what if it is connected. Learn how to drop a user when it is connected to the database as well as when it is not connected, along with the cascade drop and introduction of Startup RESTRICT mode of Oracle database. ------------------------- Topics cover 1. Drop user when it is not connected to the database 2. Drop user cascade 3. Drop user when it is connected to the database 4. How to kill a session 5. Oracle Start-up Restrict 6. What is Restrict Start-up and why we use it. Please please LIKE and SHARE my videos it makes me happy. Links: Detail Blog (Must Read) http://bit.ly/drop-user Tutorial 38 Create user using SQL Developer http://youtu.be/GS4udgR44Ls Tutorial 37 Create user using SQL create user statement http://youtu.be/4QbK2Y-1LZw Tutorial 39 create user using EM http://youtu.be/zGjh-Bb3HrI Copy Cloud referral link || Use this link to join copy cloud and get 20GB of free storage https://copy.com?r=kb4rc1 Amazon Wishlist: http://bit.ly/wishlist-amazon Follow What I am up to as it happens on Twitter https://twitter.com/rebellionrider Instagram http://instagram.com/rebellionrider Facebook. https://www.facebook.com/imthebhardwaj Linkedin. http://in.linkedin.com/in/mannbhardwaj/ You can also Email me at [email protected] Thanks for liking, commenting, sharing and watching more of our videos This is Manish from RebellionRider.com
Views: 21187 Manish Sharma
Oracle Database Constraints ON DELETE CASCADE & more
 
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Oracle Database Constraints ON DELETE CASCADE /ON DELETE set null maxvlearn.com
Views: 443 khaled alkhudari
113. ON DELETE CASCADE in SQL (Hindi)
 
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Please Subscribe Channel Like, Share and Comment Visit : www.geekyshows.com
Views: 7795 Geeky Shows
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: 11402 Caleb Curry
Часть 0. Oracle Database. Установка Oracle Linux 7 1 в Virtual Box и установка Oracle XE
 
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Видео-мануал по установке Oracle Linux в VirtualBox и установка Oracle XE. Содержимое файлов настроек и скрипты: Содержимое файла .bash_profile. Открываем: nano /root/.bash_profile Вставляем: #Oracle install specific environment settings umask 022 TMP=/tmp; export TMP TMPDIR=$TMP; export TMPDIR ORACLE_HOSTNAME=localhost.localdomain; export ORACLE_HOSTNAME ORACLE_BASE=/u01/app/oracle; export ORACLE_BASE ORACLE_HOME=/u01/app/oracle/product/11.2.0/xe; export ORACLE_HOME ORACLE_SID=orcl; export ORACLE_SID ORACLE_TERM=xterm; export ORACLE_TERM PATH=$ORACLE_HOME/bin:/usr/sbin:$PATH; export PATH LD_LIBRARY_PATH=$ORACLE_HOME/lib:/lib:/usr/lib; export LD_LIBRARY_PATH CLASSPATH=$CLASSPATH:$ORACLE_HOME/JRE:$ORACLE_HOME/jlib:$ORACLE_HOME/rdbms/jlib; export CLASSPATH NLS_LANG=AMERICAN_AMERICA.CL8MSWIN1251; export NLS_LANG Ctrl+O сохранить, Ctrl+X выйти из nano. В mc - F4 редактировать файл, F2 - сохранить, F10 выйти Открываем порт 1521 и 8080 в Firewall на Oracle Linux 7.1: firewall-cmd --zone=public --add-port=1521/tcp --permanent ; firewall-cmd --zone=public --add-port=8080/tcp --permanent ; firewall-cmd --reload ; firewall-cmd --zone=public --list-ports Должно быть так: success success success 1521/tcp 8080/tcp Команды создания пользователя вставляем в SQL Navigator или SQL Developer: --DROP USER analytic CASCADE; --Это удаление пользователя и всех его данных. CREATE USER analytic IDENTIFIED BY 123456; --123456 - это пароль. GRANT CREATE SESSION TO analytic; --право подключаться. Ѕез него невозможно залогиниться в Oracle --под этим пользователем. GRANT CREATE TABLE TO analytic; --право создавать таблицы GRANT CREATE PROCEDURE TO analytic; --право создавать процедуры GRANT CREATE TRIGGER TO analytic; --право создавать триггеры GRANT CREATE VIEW TO analytic; --право создавать представления GRANT CREATE SEQUENCE TO analytic; --право создавать последовательности GRANT CREATE LIBRARY TO analytic; --право создавать внешние процедуры/библиотеки GRANT CREATE ANY DIRECTORY TO analytic; GRANT DROP ANY DIRECTORY TO analytic; --право создавать, удалять, читать и писать в директории GRANT CREATE PUBLIC SYNONYM TO analytic; GRANT EXECUTE ON SYS.UTL_HTTP TO analytic; GRANT EXECUTE ON SYS.UTL_FILE TO analytic; GRANT EXECUTE ON SYS.utl_smtp TO analytic; GRANT EXECUTE ON SYS.utl_xml TO analytic; --права на использование пакетов ALTER USER analytic QUOTA UNLIMITED ON USERS; ALTER USER analytic QUOTA UNLIMITED ON SYSTEM; --раздаем квоты на использование места - неограничено. COMMIT; --подтверждение сделанных в данной сессии операций Access Control List не могу опубликовать, с видео тащите. Гугл не позволяет писать скобки в описании видео. Но в принципе ACL и не нужен большинству из вас.
Oracle SQL Tutorial 18 - How to Create Foreign Keys
 
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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: 20104 Caleb Curry
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: 7959 Caleb Curry
USER MANAGEMENT CREATE USER DROP USER   CASCADE
 
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USER MANAGEMENT HOW TO CREATE A USER ===================== create user naveen identified by naveen; create user pavan identified by pavan default tablespace king; HOW TO DROP USER ================= drop user naveen; (it will work if no objects) drop user pavan cascade; HOW TO GRANT ORACLE PREDEFINED ROLES TO USER ============================================ grant connect,resource to naveen; select * from session_privs; set lines 180 pages 200 col username for a30 select username,default_tablespace,temporary_tablespace from dba_users where username like '&user';
Views: 391 Praveen Biyyapu
Oracle 12c New Feature On Delete Cascade
 
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oracle 12c new features for developers Oracle 12c New Feature On Delete Cascade
Views: 95 Siva Academy
How to Create Cascade LOV (List of Values) in  ADF
 
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Cascading List of Values in Oracle ADF
Views: 2364 Venky P
HOW TO CREATE USER IN ORACLE AND DROP IT
 
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by Kumar:Oracle This video will tell you how to create user and grant him dba privilege to the created user , and how to drop it.
Views: 534 brijesh kumar
Example on foreign key constraint and delete cascade
 
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Join discussion on http://www.techtud.com/video-illustration/following-table-has-two-attributes-and-c-where-primary-key-and-c-foreign-gate
Views: 7724 Techtud
Foreign Key, Drop Foreign Key in SQL & Cascade Vs Restrict Property
 
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In this lecture our topic is Foreign Key, Drop Foreign Key in SQL & Cascade Vs Restrict Property. This course is first (fundamental to advance) course on database management systems and structured query language. Complete SQL implementation with XAMPP. Advance projects are also included in this course. The course discusses different topics of the databases. We will be covering both the theoretical and practical aspects of databases. Our website: http://www.exceptionalprogrammers.com Facebook: https://www.facebook.com/ExceptionalProgrammers/ G mail: [email protected]
Oracle - SQL - Drop Table
 
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Oracle - SQL - Drop Table Watch more Videos at https://www.tutorialspoint.com/videotutorials/index.htm Lecture By: Mr. Anadi Sharma, Tutorials Point India Private Limited.
Cascading List of Values with Oracle ADF
 
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How to define one LOV that depends on the value of another LOV and implement the UI in a JSF application
Views: 27086 ShayJDev
Difference Between Delete and Truncate
 
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Below is link for Useful Pl/SQL Books http://goo.gl/XMy0tt ---------------------------------------------------------- Difference Between Delete and Truncate in Detail On bigger picture they serve the same purpose but there are many Differences listed with examples Point Delete Truncate 1. Data Recovery Delete: Come under the DML Category, we need to commit or Rollback explicitly to make the changes permanent, so we can recover the data by Rollback command fully with in a session or up to a point if Save Points are used Fall In DDL Category (DDL Command issue the Auto commit implicitly) so no chances of Recovery even not using the Flashback table method. But Truncate operations are also logged , they didn’t generate redo SQL but they are logged , view for truncated data info V$LOGMNR_CONTENTS 2. Data Removal Delete Can remove all or selected data using the Where Clause predicates. Or we can say delete any subset of rows We can Truncate complete table or a partition or sub partition of a table. 3. Speed Delete is Slower because oracle maintain the redo logs for Read Consistency (so that every session connected can see a consistent data at a given point of time ) Delete is very time consuming activity especially when table have numerous indexes and Triggers associated with table Faster as no data logs are maintained no associated trigger firing. 4. DML Triggers Firing DML (Delete) triggers associated with table will fire. DML Trigger will not fire in case of truncate method. 5. Flashback Technology Data can be recovered even after commit operation using Flashback Table options Flashback_transaction_query table will give what to recover and up to which point. Data cannot be recovered in truncate method by Flashback table option. 6. Referential Integrity Constraint Behavior if we don’t have related data in child table then we can delete the data from the parent table or we have variants like On Delete Cascade & on Delete set Null. We can’t truncate a table with enable Referential Integrity Constraint, even there is no data in the child table, we have to disable or drop the constraint if we want to truncate the table. Exception: Truncate is possible if the FK is self-referential means primary key and foreign key are on the same table. 7. Space De allocation or Space Utilization No extent reset with delete when deleting rows from a table, extents are not de allocated, So if there were 50 extents in the table before the deletion, there will still be 50 after the deletion. Truncate: When a table is truncated it will free the space allocated except in case of reuse storage clause. This space can subsequently be used only by new data in the table or cluster resulting from insert or update operations .All extents are de allocated leaving only the extents specified when the table was originally created .Example So if the table was originally created with min extents 3, there will be 3 extents remaining when the tables is truncated. When you truncate a table, NEXT is automatically reset to the last extent deleted. 8. High Water Mark Delete will not reset the high water mark Truncate will reset the High Water mark which is very important for performance point of view as in case of full table scan and full index scan oracle will read all the block under high water mark this makes a lot of difference in terms of performance. 9. Cluster No as such restriction with delete. You cannot individually truncate a table that is part of a cluster. You must truncate the cluster, Delete all rows from the table, or drop and re-create the table. 10. Information Capturing Delete : we can capture the row information what we have deleted using Delete Method, f you are deleting multiple records then use composite data types (collections & records) Truncate Don’t have this feature of capturing the deleted records. 11. Function Based Index Impact DELETE You cannot delete rows from a table if a function-based index on the table has become invalid. You must first validate the function-based index. Truncate: No as such restriction 12. UNUSABLE Indexes Delete no as such feature. Truncate if table is not empty then truncate make all unusable indexes to useable. 13. Complex views You cannot delete data from a Complex view except through INSTEAD OF triggers. But we can delete data from simple Views and MV. We cannot truncate a view simple or complex but you can truncate MV with special Features like Preserve MV Logs and Purge MV Logs. 14. Privileges Delete You need to provide delete table privilege on object. Truncate you must have drop table privilege there is no truncate table privilege exists. 15. Domain Index No as such restriction You cannot truncate the object having domain index in invalid or In progress state
Views: 12824 Ram Gupta
Oracle - SQL - Check Constraint
 
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Oracle - SQL - Check Constraint Watch more Videos at https://www.tutorialspoint.com/videotutorials/index.htm Lecture By: Mr. Anadi Sharma, Tutorials Point India Private Limited.
Oracle Foreign key Constraint تعليم اوراكل
 
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by Mohamed El Desouki - محمد الدسوقى [email protected] Tel :00966 553450836 جامعة سلمان بن عبد العزيز - السعودية - الخرج How To Combine two tables using Foreign Key Constraint.ربط الجداول بإستخدام قيد Text Book: Fundamentals of Database Systems, 5th Edition, by Elmasri/Navathe, published by Addison-W oracle create table statement oracle drop table statement oracle constraints database constraints primary key constraint foreign key constraint check constraint null not null constraint unique constraint
ON DELETE CLAUSE OF FOREIGN KEY CONSTRAINT IN ORACLE SQL WITH EXAMPLE (CASCADE/SET NULL/NO ACTION)
 
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This is a free video tutorial explaining about the nonmandatory on delete clause in the foreign key constraint in Oracle SQL database, the video explains about how the on delete set null and on delete cascade works, how it can be implemented with easy to understand examples. We have also shown practical demonstration on creating the foreign key constraint, and then deleting the data from the parent table and observing the changes that take place in the child table.
Views: 1300 Kishan Mashru
SQL tutorials 17: SQL Primary Key constraint,  Drop primary Key
 
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Blog link: http://www.rebellionrider.com/sql-primary-key.htm SQL tutorial on Primary key / SQL Primary key, In this tutorial you will learn about simple primary key, composute primary key, how to drop primary key. defining primary key using create table and alter table along with many other things. 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 So Primary Key There are two types of Primary keys First is Simple primary Key: Primary key which Involves only one column and Second is Composite Primary Key: Primary Key which involves more than one column. We will start with Simple primary key. You can create Primary key either with Create Table statement of by using Alter table Statement. Let's define simple primary key using create table statements. With create table statement we can either define primary key at column level or at table level. We will start with defining Primary key at column level using create table statement. You just have to put keyword Primary key after data type and size of column while defining a column of a table. Here oracle server will create a primary key on product id with default constraint name which will be slightly difficult to understand. You can give your own name to your constraint which is also a good practice.
Views: 97972 Manish Sharma
56. ALTER TABLE to ADD and DROP integrity constraints in PL/SQL Oracle
 
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In this video you will learn about ALTER TABLE to ADD and DROP integrity constraints 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: 3301 ITORIAN
Oracle - SQL - Truncate Table
 
02:26
Oracle - SQL - Truncate Table Watch more Videos at https://www.tutorialspoint.com/videotutorials/index.htm Lecture By: Mr. Anadi Sharma, Tutorials Point India Private Limited.
2.ORACLE WORLD - Recovery of Drop Table with purge condition using Current SCN Number in Flashback
 
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Hello friends in this video we learn about that how to recover a permanent dropped table using current SCN number in Oracle database using Flashback Technology ... #RecoveryofDropTable #performingflashback By Lalit saini
Views: 2451 Oracle World
Oracle - SQL - Foreign Key Constraint
 
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Oracle - SQL - Foreign Key Constraint Watch more Videos at https://www.tutorialspoint.com/videotutorials/index.htm Lecture By: Mr. Anadi Sharma, Tutorials Point India Private Limited.
How to drop user Oracle || Ra soft
 
03:06
How to drop user Oracle #tags Graphics Design,logo design,Ra soft,Technology,Adobe photoshop,How to design Logo,Logo design,adobe illustrator tutorial,Create logo,How to design,Design logo,create,How to design logo,illustrator,water drops,Drop shadow,Create a logo,RA Soft Technology,Ra Technology,Robi logo,How to Create LOV,Create LOV,How to oracle 10g Uninstall,Oracle 10g Unistall,How to add hyper link oracle forms,oracle forms add website link,how to add hyper link oracle 10g,oracle forms add hyper link.
Views: 481 RA Soft
Creating  Managing  Droping Oracle Database Tablespaces
 
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Creating Managing Droping Oracle Database Tablespaces select tablespace_name,block_size,status,contents,logging from dba_tablespaces; create tablespace mytbs datafile 'd:\oradata\dbrdbms\mytbs01.dbf' size 10m; alter tablespace mytbs add datafile 'd:\oradata\dbrdbms\mytbs02.dbf' size 10m; alter tablespace mytbs drop datafile 'd:\oradata\dbrdbms\mytbs02.dbf'; desc v$datafile; desc ts#,name from v$datafile; select ts#,name from v$tablespace; select v$datafile.ts#,v$datafile.name,v$tablespace.name from v$datafile,v$tablespace where v$datafile.ts#=v$tablespace.ts# and v$tablespace.name='MYTBS'; alter database datafile 'd:\oradata\dbrdbms\mytbs01.dbf' resize 20m; ALTER DATABASE DEFAULT TABLESPACE mytbs; select ts#,name from v$tablespace; select ts#,name from v$datafile; select ts#,name from v$tablespace; drop tablespace mytbs; drop tablespace mytbs ialtncluding contents and datafiles; drop tablespace mytbs including contents and datafiles cascade; alter tablespace mytbs read only; alter tablespace mytbs read write; alter tablespace mytbs force logging; alter tablespace mytbs nologging; alter tablespace mytbs flashback on; alter tablespace mytbs flashback off; purge tablespace mytbs user myuser;
Views: 20792 Abbasi Asif
Oracle SQL Tutorial 20 - How to Create Composite Primary Keys
 
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This video is going to be a tutorial on how to create composite and compound keys. The difference between a composite and compound key is that a composite key can consist of any columns while a compound key has to consist of columns that are all keys themselves. We will be working with a compound key because we are going to be using the an intermediary table that has two foreign keys. The combination of both of the keys have to be unique. First, if we have any other CREATE TABLE commands, we are going to comment those out. We will space out the CREATE TABLE to have each column on a line, then we will add constraints as needed. CREATE TABLE project_users( project_id, user_id ) Now, let's add the data types: CREATE TABLE project_users( project_id NUMBER, user_id NUMBER } Now, what about some column attributes? I'm going to make both of the columns NOT NULL because we always want the rows to have a user and a project: CREATE TABLE project_users( project_id NUMBER NOT NULL, user_id NUMBER NOT NULL } Now, let's add the foreign key constraints. Now, what do we name these? We are going to add a primary key that covers both of these columns, so I'm going to be a sinner and not give these constraints names: CREATE TABLE project_users( project_id NUMBER NOT NULL REFERENCES projects (project_id), user_id NUMBER NOT NULL REFFERENCES users (user_id) ) Now, the way we have it now is that if we delete a project in the project table, and there are any rows in the project_users table, it will throw an error and prevent deletion. I would prefer for it to also delete any project members. That would make sense because if you delete a project we want it to delete the associate between that project and certain users. The same goes for if we delete a user, we want their association with a certain project to be deleted. To do this, we need to add the ON DELETE command: 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, ) Finally, let's learn how to create a compound or composite key. literally, the only difference is that you put a comma and add the second table inside of the parenthesis. 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) ) Now, the combination of project_id and user_id cannot be null, is always unique, and has an index. The only thing we should do now is add a few indexes. We aren't done yet...In the next video we are going to figure out what columns would benefit from indexes and we'll add them to it. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 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: 9945 Caleb Curry
SQL tutorials 18: SQL Foreign Key Constraint
 
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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: 99996 Manish Sharma
24. Referential Integrity in Oracle
 
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In this video you will learn about Referential Integrity in Oracle. You will learn how to create Primary Key and Foreign Key. There will be Foreign Key in the child table that will reference Primary Key in master/parent table. You will also learn how to delete all the records from child table when related record is parent/master table is deleted. If you try to insert any record which is not available in master/parent table child table will ignore insert command. 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: 26191 ITORIAN
How To Create & Drop user By Oracle 11g
 
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How To Create & Drop user By Oracle 11g this is the orginal oracle tutorial Content.. Create BY: Rakib Uddin Niloy
Views: 269 Apex Helpline
SQL 12c Tutorial 22 : SQL 12c Feature TRUNCATE TABLE With CASCADE option
 
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SQL 12c Tutorial 22 : SQL 12c Feature TRUNCATE TABLE With CASCADE option SQL 12c New Features SQL 12c Tutorial for beginners Oracle SQL 12c Tutorial for beginners
Views: 495 TechLake
How to create Foreign Key Constraint with ON DELETE CASCADE in SQL Server - SQL Server Tutorial 80
 
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SQL Server / T-SQL Tutorial Scenario: You are working as SQL Server developer, you need to create two tables with Primary -Foreign Key Relationship. You want to create Foreign Key Constraint with setting if record will be deleted from Referenced Table (Primary Key Column Table), it should be deleted from Parent Table ( Foreign Key Constraint Table) as well. Link to scripts used in SQL Server / TSQL Tutorial Video http://www.techbrothersit.com/2016/04/how-to-create-foreign-key-constraint_29.html Check out our website for Different SQL Server, MSBI tutorials and interview questions such as SQL Server Reporting Services(SSRS) Tutorial SQL Server Integration Services(SSIS) Tutorial SQL Server DBA Tutorial SQL Server / TSQL Tutorial ( Beginner to Advance) http://www.techbrothersit.com/
Views: 2957 TechBrothersIT
Tutorial 14- ON DELETE RESTRICT AND CASCADE
 
08:37
Learn About ON DELETE RESTRICT AND ON DELETE CASCADE in PostgreSQL.
Views: 13819 Programming Guru
6-Add Drop Modify Rename Disable Enable truncate  unused column Cascade Update Delete.avi
 
28:00
Columns -- Constraints -- Add Drop Modify Rename Disable Enable truncate -- unused column -- Cascade Update Delete.
Views: 1511 Adel Sabour
PostgreSQL - Drop all tables of a Database
 
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drop schema public cascade; create schema public;
Views: 2589 Bhaskar Reddy Pulsani
Oracle Database Users / User Management (Simple)
 
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Create, Alter, Drop, Grant Rights, Default Tablespace, Temporary Tablespace, Quota Setup, View Users Information, Lock / Unlock user account select username,account_status,default_tablespace, temporary_tablespace,created from dba_users; create user myuser identified by myuser; alter user myuser quota unlimited on mytbs; alter user myuser quota 100m on mytbs; alter user temporary tablespace temp; alter user myuser default tablespace mytbs; alter user myuser accout unlock; alter user myuser account lock; alter user myuser password expire; alter user myuser identified by youuser; create user myuser identified by myuser default tablespace users temporary tablespace temp quota unlimited on users; grant create session, resource to myuser; grant create session, resource to myuser with grant option; drop user asif; drop user asif cascade;
Views: 40899 Abbasi Asif
Oracle SQL Tutorial 15 - How to Add Primary Key Constraints
 
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The goal of this video is to take the CREATE TABLE statement we have and walk through the different ways to create primary keys. This and foreign keys are the most common constraints, so we need to make sure that you have this one down. Once we have a more complex database design with multiple tables, we will learn the proper way to create foreign keys. For now, I am going to keep all of our constraints at the column level, unnamed. The only exception is the primary key, because that is what we are focusing on in this video. The first way to create the primary key is at the column level, unnamed. The primary key is very important because it what we use to distinguish rows from one another. Every table you create is going to need a primary key, and I suggest putting a lot of effort into making sure your keys are set up correctly and organized. --Delete the table if needed: DROP TABLE users; CREATE TABLE users( user_id NUMBER PRIMARY KEY, username VARCHAR2(50 CHAR) NOT NULL UNIQUE ) The next way is at the column level, but named: --Delete the table: DROP TABLE users; CREATE TABLE users( user_id NUMBER CONSTRAINT users_pk PRIMARY KEY, username VARCHAR2(50 CHAR)NOT NULL UNIQUE ) The general naming convention here is the table name followed by an underscore, followed by pk for primary key. Finally, the third way, which is at the table level, is the way we are going to create our primary key: --Delete the table: DROP TABLE users; CREATE TABLE users( user_id NUMBER, username VARCHAR2(50 CHAR) NOT NULL UNIQUE, CONSTRAINT users_pk PRIMARY KEY (user_id) ) Now, once you've created these constraints, you can use Oracle SQL Developer to find these constraints. Open your databases in the connections tab and find the table in the Tables folder. Double click your table and travel to the Constraints tab. You can tell here that the UNIQUE constraint still exists in this table, but it has a pretty disgusting name. It kind of wants to make me puke. Referencing that constraint in the future with that wacky name would be a burden. Engrave these three options in your head so that you can use any of them whenever you need and can read other peoples' code. Thank you for sticking with the series thus far. In the next video, we will be…doing something. See you then! :) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 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: 13581 Caleb Curry
SelectTec | Aula Nº 30 | Alter table add Foreign Key - Oracle SQL Developer
 
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syntax: ALTER TABLE table_name ADD CONSTRAINT constraint_name FOREIGN KEY (column1, column2, ... column_n) REFERENCES parent_table (column1, column2, ... column_n);
Views: 1867 SelectTec
Oracle Constraints
 
27:50
Oracle SQL Tutorials For Full Course Experience Please Go To http://mentorsnet.org/course_preview?course_id=4 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: 20159 Oresoft LWC
Primary (PK) and Foreign Key (FK) Relation on Table without Cascade Rules Part 2 | MSSQL Training
 
20:42
Primary (PK) and Foreign Key (FK) Relation on Table without Cascade Rules Part 2 | MSSQL Training | Mr.Sudhakar L ►For Registration : https://goo.gl/r6kJbB ►Call: +91-8179191999 ► Visit Our Website: http://nareshit.in/ http://nareshit.com/ ► About NareshIT: "Naresh IT is the Best Software Training Institute for Hadoop, Salesforce, AWS, DevOps, Sprak, 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 Hyderabad, Chennai and Vijayawada, India which provides online and classroom training classes" ►For Registration : https://goo.gl/r6kJbB ►Call: India- 8179191999, USA- 404-232-9879 Email: [email protected] ►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 Video's of each and every session. 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 ► Visit Our Website: http://nareshit.in/ http://nareshit.com/
Views: 4407 Naresh i Technologies
FOREIGN KEY CONSTAINT IN ORACLE SQL
 
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This is a free video tutorial explaining about foreign key constraint in Oracle SQL database, the video explains about how the foreign key works, how it can be implemented with easy to understand examples. We have also shown practical demonstration on creating the foreign key constraint, and then encountering the part not found, and child record exists kind of integrity constraint.
Views: 581 Kishan Mashru
SelectTec | Aula Nº 32 | Continuação Cascade/Restrict - Oracle SQL Developer
 
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ALTER TABLE table_name ADD CONSTRAINT constraint_name FOREIGN KEY (column1, column2, ... column_n) REFERENCES parent_table (column1, column2, ... column_n) ON DELETE CASCADE;
Views: 980 SelectTec
How to Resolve Oracle SQL Parent Key Not Found (ORA-02291)
 
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In this video, we’ll explain what the ORA-02291 “parent key not found” error is, see an example, and look at how to resolve it. This error usually happens when we try to insert data into a table. It looks like this: Error is: ORA-02291: integrity constraint (constraint_name) violated - parent key not found So what does this error mean? It means we’re trying to insert data into a child table, and there is no related record in the parent table. If a foreign key has been set up to enforce this relationship, there needs to be a parent to insert a child that refers to it. Watch the video to see an example of this error as well as how to resolve it. For more information on Oracle SQL, refer to the Database Star website here: https://www.databasestar.com/
Views: 1754 Database Star
SQL Delete row | SQL Update Query | sql queries tutorial in hindi | DBMS Lectures in hindi  #75
 
06:09
Welcome to series of gate lectures by well academy SQL Delete row | SQL Update Query | sql queries tutorial in hindi | DBMS Lectures in hindi #75 Here are some more GATE lectures by well academy relational algebra in dbms | relational algebra operations in dbms | DBMS lectures in hindi #58 : https://youtu.be/zbnyudmh4ys Select Operation in Relation Algebra | Selection in Relational Algebra | DBMS lectures in hindi #59 : https://youtu.be/NsIL7z4Ck4A Projection in Relational Algebra | relational algebra in dbms | DBMS Lectures in hindi #60 : https://youtu.be/5QVMyeDfih4 Gate 2012 Relaional Algebra | relational algebra in dbms gate | DBMS lectures in hindi #61 : https://youtu.be/SeGqtlzy5_k Rename operation in Relational Algebra | relational algebra in dbms | DBMS Lectures in hindi #62 : https://youtu.be/0bklGoIBcQ8 set operations in dbms | Set Operations in Relational Algebra in dbms | DBMS lectures in hindi #63 : https://youtu.be/cE8mZnWxyN4 Join Operation in DBMS | join operation in relational algebra | join operation in database DBMS #64 : https://youtu.be/Au-ab_Yq1rw Natural join operation in dbms | Natural join in relational algebra | Natural join in hindi | #65 : https://youtu.be/rBaSaPoUeqQ Division Operation | Division Operation in DBMS | Division Operation in dbms with example | DBMS #66 : https://youtu.be/705ljW1X5gM join in dbms | Types of Join in dbms | join operation in relational algebra | DBMS lectures #67 : https://www.youtube.com/watch?v=4DppvRx5a2Y GATE 2015 Relational Algebra | relational algebra in dbms with examples | DBMS Lectures in hindi #68 : https://youtu.be/gj0xiXmjVaw Relational Calculus | relational calculus database | relational calculus in hindi | DBMS #69 : https://youtu.be/1hG_qqckYj0 Tuple Relational Calculus | tuple relational calculus in dbms | tuple relational calculus in hindi : https://youtu.be/RzGg0fykY3I Tuple Relational Calculus | Bounded Variables and Free Variables | DBMS Lectures in Hindi #71 : https://youtu.be/Yjz10ysczUc SQL create table in hindi | SQL tutorial in hindi | DBMS Lectures in hindi #72 : https://youtu.be/Pm8XAQYDBGw constraints in dbms | constraints in sql in hindi | DBMS Lectures in Hindi #73 : https://youtu.be/kevkLGrJvUg sql insert command | sql insert into table | sql insert query | DBMS Lectures in hindi #74 : https://youtu.be/lsxyUFjh148 Click here to subscribe well Academy https://www.youtube.com/wellacademy1 GATE Lectures by Well Academy Facebook Group https://www.facebook.com/groups/1392049960910003/ Thank you for watching share with your friends Follow on : Facebook page : https://www.facebook.com/wellacademy/ Instagram page : https://instagram.com/well_academy Twitter : https://twitter.com/well_academy sql delete, sql delete button, sql delete cascade, sql delete column, sql delete column data, sql delete comment, sql delete database, sql delete duplicate rows, sql delete duplicate rows from table, sql delete duplicates, sql delete from multiple tables in one statement, sql delete multiple rows, sql delete query, sql delete row, sql delete table, sql delete trigger example, sql update query, sql update table, basic sql queries tutorial, sql join queries tutorial, sql queries tutorial for beginners, sql queries tutorial for beginners in hindi, sql queries tutorial hindi, sql queries tutorial in hindi, dbms basic queries, dbms queries, dbms queries examples, dbms queries tutorial, dbms queries tutorial in hindi, dbms queries with examples, dbms sql queries, dbms sql queries in hindi, queries in dbms in hindi
Views: 6402 Well Academy
Oracle Database Bangla Tutorials 21 :: Constraint Primary key
 
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www.facebook.com/oracle.shohag Email : [email protected] Website : www.oraclebangla.com Topics : Constraint Primary key
Views: 1308 Oracle Bangla
Oracle SQL Tutorial 14 - Column-Level and Table-Level Constraints
 
04:15
In the previous video we talked about adding constraints at the column-level. We made it nice and simple by only requiring a few keywords, but the problem we were having is that we could not assign a name to the constraint, which many people like to do so we can reference easily if we need to at a later time. To do this, it requires a little bit more typing, but it will give us extra flexibility and many consider it to be the higher quality approach to adding constraints. Let's go though a simple example. Let's say we have a users table with a user_id column that we want to make a primary key. We will create the table like this: CREATE TABLE( user_ id NUMBER PRIMARY KEY ) Instead of adding the PRIMARY KEY keywords after the data type, we add: CONSTRAINT user_pk PRIMARY KEY Now, we have assigned the name user_pk to this constraint. You can do the same with other constraints, such as UNIQUE. The syntax would be CONSTRAINT username_un UNIQUE. The other way to create constraints requires to put all of our constraints at the bottom of our table creation rather than inline with the column. This type of constraint is known as a table-level constraints. To make a column a primary key using table-level constraints, we add it to the CREATE TABLE command as if it is another row and use the CONSTRAINT keyword to tell Oracle that what is coming is a constraint, not a column in our table. CREATE TABLE users( user_id NUMBER, username VARCHAR2(50 CHAR), CONSTRAINT username_un UNIQUE (username), CONSTRAINT users_pk PRIMARY KEY (user_id) ) The primary differences here is that you have to put the column you are talking about in parenthesis after the PRIMARY KEY keyword. That's because it's at the end of the table and you need a way to tell it what column you are talking about. The option of putting it at the end of the table has the added benefit in this situation because if we needed to have a primary key that is the combination of multiple columns, we can do that by just adding the other column in the PRIMARY KEY parenthesis right after a comma. In summary, there are three ways to make constraints. The first is at the column level, unnamed. The second is at the column level, named. The third is at the table level, also named. In the next video we are going to create a named constraint in Oracle SQL Developer, so stay tuned and be sure to subscribe! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 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: 13876 Caleb Curry

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