关于约束ENABLE NOVALIDATE的一个疑问
CREATE TABLE test
(id varchar2(12),
name varchar2(30) ,CONSTRAINT pk_test PRIMARY k
ALTER TABLE test disable CONSTRAINT pk_test
然后向表中插入两条完全一样的数据并commit
我的印象是ENABLE NOVALIDATE并不检查已经存在的数
SQL> ALTER TABLE test enable novalidate constra
ALTER TABLE test enable novalidate CONSTRAINT p
*
ERROR 位于第 1 行:
ORA-02437: 无法验证 (DBO.PK_TEST) - 违反主键
参考hrb_qiuyb文章
SQL> CREATE TABLE t(a INT,b varchar2(20));
TABLE created.
SQL> INSERT INTO t VALUES(1,'lijie');
1 ROW created.
SQL> ALTER TABLE t ADD constraints pk_t_a PRIMARY KEY(a);
TABLE altered.
SQL> SELECT constraint_name,constraint_type,STATUS FROM user_constraints
WHERE TABLE_NAME='T';
CONSTRAINT_NAME C STATUS
------------------------------ - --------
PK_T_A P ENABLED
SQL> SELECT index_name,uniqueness FROM user_indexes WHERE TABLE_NAME='T';
INDEX_NAME UNIQUENES
------------------------------ ---------
PK_T_A UNIQUE
SQL> ALTER TABLE t disable constraints pk_t_a;
TABLE altered.
SQL> SELECT constraint_name,constraint_type,STATUS FROM user_constraints
WHERE TABLE_NAME='T';
CONSTRAINT_NAME C STATUS
------------------------------ - --------
PK_T_A P DISABLED
SQL> SELECT index_name,uniqueness FROM user_indexes WHERE TABLE_NAME='T';
no ROWS selected
SQL> INSERT INTO t VALUES(1,'tina');
1 ROW created.
SQL> ALTER TABLE t enable novalidate constraints pk_t_a;
ALTER TABLE t enable novalidate constraints pk_t_a
*
ERROR at line 1:
ORA-02437: cannot validate (TAOBAO.PK_T_A) - PRIMARY KEY violated
这里问题是：primary key所依赖的唯一键索引起的.
解决方法：
SQL> CREATE TABLE t2 AS (SELECT * FROM t WHERE 1=0);
TABLE created.
SQL> CREATE INDEX ind_t2_a ON t2(a);
INDEX created.
SQL> INSERT INTO t2 VALUES(1,'lijie');
1 ROW created.
SQL> ALTER TABLE t2 ADD constraints pk_t2_a PRIMARY KEY(a);
TABLE altered.
SQL> SELECT constraint_name,constraint_type,STATUS FROM user_constraints
WHERE TABLE_NAME='T2';
CONSTRAINT_NAME C STATUS
------------------------------ - --------
PK_T2_A P ENABLED
SQL> SELECT index_name,uniqueness FROM user_indexes WHERE TABLE_NAME='T2';
INDEX_NAME UNIQUENES
------------------------------ ---------
IND_T2_A NONUNIQUE
SQL> ALTER TABLE t2 disable constraints pk_t2_a;
TABLE altered.
SQL> SELECT constraint_name,constraint_type,STATUS FROM user_constraints
WHERE TABLE_NAME='T2';
CONSTRAINT_NAME C STATUS
------------------------------ - --------
PK_T2_A P DISABLED
SQL> SELECT index_name,uniqueness FROM user_indexes WHERE TABLE_NAME='T2';
INDEX_NAME UNIQUENES
------------------------------ ---------
IND_T2_A NONUNIQUE
SQL> INSERT INTO t2 VALUES(1,'tina');
1 ROW created.
SQL> ALTER TABLE t2 enable validate constraints pk_t2_a;
ALTER TABLE t2 enable validate constraints pk_t2_a
*
ERROR at line 1:
ORA-02437: cannot validate (TAOBAO.PK_T2_A) - PRIMARY KEY violated
SQL> ALTER TABLE t2 enable novalidate constraints pk_t2_a;
TABLE altered.
Posted on 2008-09-11 at 下午 3:21 | Filed: 数据库 |
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