看了应该就明白了
SQL> select * from a1;BBB
----------
101
102
103
104
105SQL> select * from a2;BBB CCC
---------- --------------------
103
105
107
101
SQL> update a2 set a2.ccc=(select a1.bbb from a1 where a1.bbb=a2.bbb);已更新4行。SQL> select * from a2;BBB CCC
---------- --------------------
103 103
105 105
107
101 101
SQL> select * from a1;BBB
----------
101
102
103
104
105SQL> select * from a2;BBB CCC
---------- --------------------
103
105
107
101
SQL> update a2 set a2.ccc=(select a1.bbb from a1 where a1.bbb=a2.bbb);已更新4行。SQL> select * from a2;BBB CCC
---------- --------------------
103 103
105 105
107
101 101
解决方案 »
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