ORA-02273: this unique/primary key is referenced by some foreign keys

关于ORA-02273错误，以前还真没有仔细留意过。昨天遇到了这个问题，遂顺便总结一番，以后遇到这类问题就可以直接用下面方案解决。如下所示，我们首先准备一下测试环境。

CREATE TABLE TEST.TEST 

(  OWNER            VARCHAR2(30),

   OBJECT_ID        NUMBER,

   OBJECT_NAME      VARCHAR2(30) 

);

CREATE INDEX TEST.IX_TEST_N1 ON TEST.TEST(OBJECT_ID)  TABLESPACE TEST_DATA;

ALTER TABLE TEST.TEST ADD CONSTRAINT PK_TEST PRIMARY KEY (OBJECT_ID) USING INDEX TABLESPACE TEST_DATA;

CREATE TABLE TEST.RF_TEST

(

    ID           NUMBER,

    OBJECT_ID    NUMBER

);

ALTER TABLE TEST.RF_TEST ADD CONSTRAINT PK_RF_TEST  PRIMARY KEY(ID) USING INDEX TABLESPACE TEST_DATA;

ALTER TABLE TEST.RF_TEST ADD CONSTRAINT FK_RF_TEST FOREIGN KEY(OBJECT_ID ) REFERENCES TEST.TEST(OBJECT_ID);

如下所示，由于脚本上面的原因（没有指定主键约束对应的索引，而且又有其他索引在主键字段上，就会产生这种情况。暂时不清楚具体原因），导致TEST.TEST的主键约束对应的索引为IX_TEST_N1。

SELECT OWNER

      ,CONSTRAINT_NAME

      ,CONSTRAINT_TYPE

      ,TABLE_NAME

      ,INDEX_NAME

FROM DBA_CONSTRAINTS

WHERE TABLE_NAME='TEST';

此时假如我们要调整表TEST.TEST的主键，那么可以用下面脚本查看一下TEST表的主外键约束关系。如下所示：

SELECT DC.OWNER           AS "PARENT_TABLE_OWNER", 

       DC.TABLE_NAME      AS "PARENT_TABLE_NAME", 

       DC.CONSTRAINT_NAME AS "PRIMARY CONSTRAINT NAME", 

       DC.STATUS          AS "PRIMARY CONSTRAINT STATUS",

       DF.CONSTRAINT_NAME AS "REFERENCED CONSTRAINT NAME", 

       DF.STATUS          AS "FOREIGN CONSTRAINT STATUS",

       DF.STATUS          AS "CHILD_TABLE_OWNER", 

       DF.TABLE_NAME      AS "CHILD_TABLE_NAME" ,

       'ALTER TABLE ' || DF.OWNER  || '.' || DF.TABLE_NAME || ' DISABLE CONSTRAINT ' || DF.CONSTRAINT_NAME || ';'

FROM   DBA_CONSTRAINTS DC, 

       (SELECT C.OWNER, 

               C.CONSTRAINT_NAME, 

               C.R_CONSTRAINT_NAME, 

               C.TABLE_NAME,

               C.STATUS

        FROM   DBA_CONSTRAINTS C 

        WHERE  CONSTRAINT_TYPE = 'R') DF 

WHERE  DC.CONSTRAINT_NAME = DF.R_CONSTRAINT_NAME 

       AND DC.OWNER =UPPER('&OWNER')

       AND DC.TABLE_NAME=UPPER('&TABLE_NAME');

删除表的主键约束时，报如下错误：“ORA-02273: this unique/primary key is referenced by some foreign keys”

SQL> ALTER TABLE TEST.TEST DROP CONSTRAINT PK_TEST;

ALTER TABLE TEST.TEST DROP CONSTRAINT PK_TEST

                                      *

ERROR at line 1:

ORA-02273: this unique/primary key is referenced by some foreign keys

我们用最上面脚本生成的禁用外键约束的脚本，禁用外键约束后，然后删除表TEST.TEST的主键约束，依然报ORA-02273错误。

如上所示，不能通过先禁用外键约束，然后删除主键约束的这样操作，搜索了相关资料后，发现只能先删除外键约束，然后才能处理主键约束。

操作步骤如下:

1: 首先生成外键约束的创建脚本，后续删除外键约束后，需要重新创建外键约束。

ORACLE 11g或以上版本使用下面脚本：

--此脚本适用于Oracle 11g

SELECT  'ALTER TABLE ' || T1_OWNER || '.' || T1_TABLE_NAME

     || ' ADD CONSTRAINT ' || T1_CONSTRAINT_NAME

     || ' FOREIGN KEY (' || T1_COLUMN_NAMES || ')'

     || ' REFERENCES ' || T2_OWNER || '.' || T2_TABLE_NAME

     || '(' || T2_COLUMN_NAMES || ');' FK_SCRIPT

FROM

    (SELECT A.OWNER     T1_OWNER

          , A.TABLE_NAME T1_TABLE_NAME

          , A.CONSTRAINT_NAME T1_CONSTRAINT_NAME

          , B.R_CONSTRAINT_NAME T2_CONSTRAINT_NAME

          -- CONCATENATE COLUMNS TO HANDLE COMPOSITE

          -- FOREIGN KEYS

          , LISTAGG(A.COLUMN_NAME,', ') 

                  WITHIN GROUP (ORDER BY A.POSITION) 

                  AS T1_COLUMN_NAMES

    FROM DBA_CONS_COLUMNS A

       , DBA_CONSTRAINTS B

    WHERE A.CONSTRAINT_NAME = B.CONSTRAINT_NAME

    AND B.CONSTRAINT_TYPE = 'R'

    GROUP BY A.OWNER 

           , A.TABLE_NAME

           , A.CONSTRAINT_NAME

           , B.R_CONSTRAINT_NAME

    ) T1,

    (SELECT A.OWNER              T2_OWNER

          , A.TABLE_NAME       T2_TABLE_NAME

          , A.CONSTRAINT_NAME T2_CONSTRAINT_NAME

          -- CONCATENATE COLUMNS FOR PK/UK REFERENCED

          -- FROM A COMPOSITE FOREIGN KEY

          , LISTAGG(A.COLUMN_NAME,', ')

               WITHIN GROUP (ORDER BY A.POSITION)

               AS T2_COLUMN_NAMES

    FROM DBA_CONS_COLUMNS A

       , DBA_CONSTRAINTS B

    WHERE A.CONSTRAINT_NAME = B.CONSTRAINT_NAME

    AND B.CONSTRAINT_TYPE IN ( 'P', 'U' )

    GROUP BY A.OWNER

           , A.TABLE_NAME

           , A.CONSTRAINT_NAME ) T2

WHERE T1.T2_CONSTRAINT_NAME = T2.T2_CONSTRAINT_NAME

  AND T1.T1_OWNER  = T2.T2_OWNER

  AND T2.T2_OWNER ='&OWNER'

  AND T2.T2_TABLE_NAME = '&TABLE_NAME';

ORACLE 11g之前版本使用下面脚本

--此脚本适用于Oracle 10g

SELECT  'ALTER TABLE ' || T1_OWNER || '.' || T1_TABLE_NAME

   || ' ADD CONSTRAINT ' || T1_CONSTRAINT_NAME

   || ' FOREIGN KEY (' || T1_COLUMN_NAMES || ')'

   || ' REFERENCES ' || T2_OWNER || '.' || T2_TABLE_NAME

   || '(' || T2_COLUMN_NAMES || ');' FK_SCRIPT

FROM

  (SELECT A.OWNER   T1_OWNER

    , A.TABLE_NAME T1_TABLE_NAME

    , A.CONSTRAINT_NAME T1_CONSTRAINT_NAME

    , B.R_CONSTRAINT_NAME T2_CONSTRAINT_NAME

    -- CONCATENATE COLUMNS TO HANDLE COMPOSITE

    -- FOREIGN KEYS [HANDLES UP TO 5 COLUMNS]

    , MAX(DECODE(A.POSITION, 1,

         A.COLUMN_NAME,NULL)) ||

      MAX(DECODE(A.POSITION, 2,', '||

         A.COLUMN_NAME,NULL)) ||

      MAX(DECODE(A.POSITION, 3,', '||

         A.COLUMN_NAME,NULL)) ||

      MAX(DECODE(A.POSITION, 4,', '||

         A.COLUMN_NAME,NULL)) ||

      MAX(DECODE(A.POSITION, 5,', '||

         A.COLUMN_NAME,NULL))

        T1_COLUMN_NAMES

  FROM DBA_CONS_COLUMNS A

     , DBA_CONSTRAINTS B

  WHERE A.CONSTRAINT_NAME = B.CONSTRAINT_NAME

  AND B.CONSTRAINT_TYPE = 'R'

  GROUP BY A.OWNER

         , A.TABLE_NAME

         , A.CONSTRAINT_NAME

         , B.R_CONSTRAINT_NAME

  ) T1,

  (SELECT A.OWNER    T2_OWNER

    , A.CONSTRAINT_NAME T2_CONSTRAINT_NAME

    , A.TABLE_NAME T2_TABLE_NAME

    -- CONCATENATE COLUMNS FOR PK/UK REFERENCED

    -- FROM A COMPOSITE FOREIGN KEY

    , MAX(DECODE(A.POSITION, 1,

         A.COLUMN_NAME,NULL)) ||

      MAX(DECODE(A.POSITION, 2,', '||

         A.COLUMN_NAME,NULL)) ||

      MAX(DECODE(A.POSITION, 3,', '||

         A.COLUMN_NAME,NULL)) ||

      MAX(DECODE(A.POSITION, 4,', '||

         A.COLUMN_NAME,NULL)) ||

      MAX(DECODE(A.POSITION, 5,', '||

         A.COLUMN_NAME,NULL))

        T2_COLUMN_NAMES

  FROM DBA_CONS_COLUMNS A, DBA_CONSTRAINTS B

  WHERE A.CONSTRAINT_NAME = B.CONSTRAINT_NAME

  AND B.CONSTRAINT_TYPE IN ( 'P', 'U' )

  GROUP BY A.OWNER

         , A.TABLE_NAME

         , A.CONSTRAINT_NAME ) T2

WHERE T1.T1_OWNER = T2.T2_OWNER

  AND T1.T2_CONSTRAINT_NAME = T2.T2_CONSTRAINT_NAME

  AND T2.T2_OWNER ='&OWNER'

  AND T2.T2_TABLE_NAME = '&TABLE_NAME';

使用上面脚本生成的脚本为

ALTER TABLE TEST.RF_TEST ADD CONSTRAINT FK_RF_TEST FOREIGN KEY (OBJECT_ID) REFERENCES TEST.TEST(OBJECT_ID);

2：生成删除外键约束的脚本

SELECT 'ALTER TABLE ' 

       || OWNER || '.' || TABLE_NAME

       || ' DROP CONSTRAINT '

       || CONSTRAINT_NAME

       ||';' CONSTRAINT_DISABLE

FROM  DBA_CONSTRAINTS

WHERE CONSTRAINT_TYPE = 'R'

AND STATUS = 'ENABLED'

AND R_CONSTRAINT_NAME IN

 (

   SELECT CONSTRAINT_NAME 

   FROM DBA_CONSTRAINTS

   WHERE CONSTRAINT_TYPE IN ('P', 'U')

    AND OWNER='&OWNER'

    AND TABLE_NAME = '&TABLE_NAME'

 ); 

执行上面脚本生成的脚本，删除外键约束。

SQL> ALTER TABLE TEST.RF_TEST DROP CONSTRAINT FK_RF_TEST;

Table altered.

3：删除表TEST.TEST的主键

SQL> ALTER TABLE TEST.TEST DROP CONSTRAINT PK_TEST;

Table altered.

SQL> SELECT OWNER 

  2        ,TABLE_NAME

  3        ,INDEX_NAME

  4  FROM DBA_INDEXES 

  5  WHERE  TABLE_NAME='TEST';

OWNER      TABLE_NAME                     INDEX_NAME

---------- ------------------------------ ------------------------------

TEST        TEST                           IX_TEST_N1

SQL> 

如下所示，这种情况下，删掉了约束，并不会删除对应的索引。所以必须手工删除该索引

4： 在表TEST.TEST上增加主键约束， 在表TEST.RF_TEST上添加外键约束。

SQL> ALTER TABLE TEST.TEST ADD CONSTRAINT PK_TEST PRIMARY KEY(OBJECT_ID) USING INDEX TABLESPACE TEST_DATA;

Table altered.

SQL> ALTER TABLE TEST.RF_TEST ADD CONSTRAINT FK_RF_TEST FOREIGN KEY (OBJECT_ID) REFERENCES TEST.TEST(OBJECT_ID);

Table altered.

SQL>