一 语法
DISABLE|ENABLE CONSTRAINT constrint_name
二 实例
sql> desc userinfo_f4名称是否为空?类型-----------------------------------------------------------------------------ID NOT NULL VARCHAR2(10)USERNAME VARCHAR2(20)TYPEID_NEW VARCHAR2(10)sql>select constraint_name,constraint_type,status from user_constraints2where table_name='USERINFO_F4';CONSTRAINT_NAME C STATUS---------------------------------------SYS_C0011062 P ENABLEDFK_TYPEID_ALTER R ENABLED
sql> alter table userinfo_f42 disable constraint FK_TYPEID_ALTER3;表已更改。status from user_constraints2where table_name='USERINFO_F4';CONSTRAINT_NAME C STATUS---------------------------------------SYS_C0011062 P ENABLEDFK_TYPEID_ALTER R DISABLED
三 语法
DROP CONSTRAINT constaint_name;
四 实例
sql> alter table userinfo_f4
2 drop constraint FK_TYPEID_ALTER;status from user_constraints2where table_name='USERINFO_F4';CONSTRAINT_NAME C STATUS---------------------------------------SYS_C0011062 P ENABLED