ON DELETE and ON UPDATE Options : Foreign Key « Constraints « SQL Server / T-SQL Tutorial

SQL Server / T-SQL Tutorial
1. Query
2. Insert Delete Update
3. Table
4. Table Join
5. Data Types
6. Set Operations
7. Constraints
8. Subquery
9. Aggregate Functions
10. Date Functions
11. Math Functions
12. String Functions
13. Data Convert Functions
14. Analytical Functions
15. Sequence Indentity
16. View
17. Index
18. Cursor
19. Database
20. Transact SQL
21. Procedure Function
22. Trigger
23. Transaction
24. XML
25. System Functions
26. System Settings
27. System Tables Views
28. User Role
29. CLR
Java
Java Tutorial
Java Source Code / Java Documentation
Java Open Source
Jar File Download
Java Articles
Java Products
Java by API
Photoshop Tutorials
Maya Tutorials
Flash Tutorials
3ds-Max Tutorials
Illustrator Tutorials
GIMP Tutorials
C# / C Sharp
C# / CSharp Tutorial
C# / CSharp Open Source
ASP.Net
ASP.NET Tutorial
JavaScript DHTML
JavaScript Tutorial
JavaScript Reference
HTML / CSS
HTML CSS Reference
C / ANSI-C
C Tutorial
C++
C++ Tutorial
Ruby
PHP
Python
Python Tutorial
Python Open Source
SQL Server / T-SQL
Oracle PL / SQL
Oracle PL/SQL Tutorial
PostgreSQL
SQL / MySQL
MySQL Tutorial
VB.Net
VB.Net Tutorial
Flash / Flex / ActionScript
VBA / Excel / Access / Word
XML
XML Tutorial
Microsoft Office PowerPoint 2007 Tutorial
Microsoft Office Excel 2007 Tutorial
Microsoft Office Word 2007 Tutorial
SQL Server / T-SQL Tutorial » Constraints » Foreign Key 
7. 3. 4. ON DELETE and ON UPDATE Options
The use of the ON DELETE and ON UPDATE options.

7>
8>
9CREATE TABLE department(
10>    dept_no CHAR(4NOT NULL,
11>    dept_name CHAR(25NOT NULL,
12>    location CHAR(30NULL,
13>    CONSTRAINT prim_dept PRIMARY KEY (dept_no))
14> GO
1>
2CREATE TABLE employee (
3>            emp_no INTEGER NOT NULL,
4>            emp_fname CHAR(20NOT NULL,
5>            emp_lname CHAR(20NOT NULL,
6>            dept_no CHAR(4NULL,
7>            CONSTRAINT prim_emp PRIMARY KEY (emp_no),
8>            CONSTRAINT foreign_emp FOREIGN KEY(dept_noREFERENCES
9>       department(dept_no))
10> GO
1>
2CREATE TABLE project (project_no CHAR(4NOT NULL,
3>            project_name CHAR(15NOT NULL,
4>            budget FLOAT NULL,
5>            CONSTRAINT prim_proj PRIMARY KEY (project_no))
6> GO
1>
2CREATE TABLE myProject(
3>       emp_no INTEGER NOT NULL,
4>       project_no CHAR(4NOT NULL,
5>       job CHAR (15NULL,
6>       enter_date DATETIME NULL,
7>       CONSTRAINT prim_works1 PRIMARY KEY(emp_no, project_no),
8>       CONSTRAINT foreign1_works1 FOREIGN KEY(emp_no)      REFERENCES employee(emp_noON DELETE CASCADE,
9>       CONSTRAINT foreign2_works1 FOREIGN KEY(project_no)  REFERENCES project(project_noON UPDATE CASCADE)
10>
11>
12> GO
1>
2> drop table myProject;
3> GO
1>
2> drop table project;
3> GO
1> drop table employee;
2> GO
1> drop table department;
2> GO
7. 3. Foreign Key
7. 3. 1. The FOREIGN KEY Clause
7. 3. 2. FOREIGN KEY Constraints
7. 3. 3. A statement that adds a foreign key constraint
7. 3. 4. ON DELETE and ON UPDATE Options
7. 3. 5. Adding a FOREIGN KEY to the Employees Table
7. 3. 6. Re-creating the FOREIGN KEY with NO ACTION (Implicitly)
7. 3. 7. Referential Constraints
7. 3. 8. Cascading Updates and Deletes
7. 3. 9. Supporting Basic Referential Integrity with Foreign Keys
www.java2java.com | Contact Us
Copyright 2009 - 12 Demo Source and Support. All rights reserved.
All other trademarks are property of their respective owners.