Oracle
CHECK Constraint
Figo Kim
2006. 11. 23. 22:05
1. Defines a condition
2. Not-Allowed expressions :
- CURRVAL, NEXTVAL, LEVEL, ROWNUM pseudocolumns
- SYSDATE, UID, USER, and USERENV functions
- Queries that refer to other values in other rows
3. A single column can have multiple CHECK constraints
2. Not-Allowed expressions :
- CURRVAL, NEXTVAL, LEVEL, ROWNUM pseudocolumns
- SYSDATE, UID, USER, and USERENV functions
- Queries that refer to other values in other rows
ex) .... , salary NUMBER(2) CONSTRAINT emp_salary_min
CHECK (salary > 0 ), .....
CHECK (salary > 0 ), .....
3. A single column can have multiple CHECK constraints