Oracle外键约束之删除外键约束

一 语法

DISABLE|ENABLE CONSTRAINT constrint_name

二 实例

1. SQL> desc userinfo_f4
2. 名称是否为空?类型
3. -----------------------------------------------------------------------------
4. ID NOT NULL VARCHAR2(10)
5. USERNAME VARCHAR2(20)
6. TYPEID_NEW VARCHAR2(10)
9. SQL>select constraint_name,constraint_type,status from user_constraints
10. 2where table_name='USERINFO_F4';
12. CONSTRAINT_NAME C STATUS
13. ---------------------------------------
14. SYS_C0011062 P ENABLED
15. FK_TYPEID_ALTER R ENABLED

1. SQL> alter table userinfo_f4
2. 2 disable constraint FK_TYPEID_ALTER
3. 3;
5. 表已更改。
7. SQL>select constraint_name,constraint_type,status from user_constraints
8. 2where table_name='USERINFO_F4';
10. CONSTRAINT_NAME C STATUS
11. ---------------------------------------
12. SYS_C0011062 P ENABLED
13. FK_TYPEID_ALTER R DISABLED

三 语法

DROP CONSTRAINT constaint_name;

四 实例

1. SQL> alter table userinfo_f4
2. 2 drop constraint FK_TYPEID_ALTER;
3.  
4. SQL>select constraint_name,constraint_type,status from user_constraints
5. 2where table_name='USERINFO_F4';
7. CONSTRAINT_NAME C STATUS
8. ---------------------------------------
9. SYS_C0011062 P ENABLED