How to create a table using constraints...
IF i change the PARENT KEY value ,then CHILD KEY
table will also to change in the another table...
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Arunkumar
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Answer Posted / rameshwari
Hi,
You can use cascade as follows
1>
2> CREATE TABLE employee (emp_no INTEGER NOT NULL
CONSTRAINT prim_empl PRIMARY KEY,
3> emp_fname CHAR(20) NOT NULL,
4> emp_lname CHAR(20) NOT NULL,
5> dept_no CHAR(4) NULL)
6>
7> CREATE TABLE project (project_no CHAR(4) NOT NULL
CONSTRAINT prim_pro PRIMARY KEY,
8> project_name CHAR(15) NOT NULL,
9> budget FLOAT NULL)
10>
11> CREATE TABLE works_on1
12> (emp_no INTEGER NOT NULL,
13> project_no CHAR(4) NOT NULL,
14> job CHAR (15) NULL,
15> enter_date DATETIME NULL,
16> CONSTRAINT prim_works1 PRIMARY KEY(emp_no,
project_no),
17> CONSTRAINT foreign1_works1 FOREIGN KEY
(emp_no) REFERENCES employee(emp_no) ON DELETE CASCADE,
18> CONSTRAINT foreign2_works1 FOREIGN KEY
(project_no) REFERENCES project(project_no) ON UPDATE
CASCADE)
19>
20> -- The creation of the works_on1 table that uses the ON
DELETE CASCADE and ON UPDATE CASCADE options.
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