This is used to insert the values based on
specified condition.
We can add this constraint in all three
levels.
Ex:
COLUMN LEVEL
SQL> create table student12(no
number(2) , name varchar(10), marks number(3) check
(marks > 300));
SQL> create table student12(no number(2) , name varchar(10), marks
number(3)
constraint ch check(marks >
300));
TABLE LEVEL
SQL> create table student12(no number(2) , name varchar(10), marks number(3),
check
(marks > 300));
SQL> create table student12(no number(2) , name varchar(10), marks
number(3),
constraint ch check(marks > 300));
ALTER LEVEL
SQL> alter table student12 add check(marks>300);
SQL> alter table student12 add constraint ch check(marks>300);
