外连接
分为左连接和右连接
例:
SQL> select * from a1;BBB
----------
101
102
103
104
105SQL> select * from a2;BBB CCC
---------- --------------------
101
102
105SQL> select * from a1,a2 where a1.bbb(+)=a2.bbb;BBB BBB CCC
---------- ---------- --------------------
101 101
102 102
105 105SQL> select * from a1,a2 where a1.bbb=a2.bbb(+);BBB BBB CCC
---------- ---------- --------------------
101 101
102 102
103
104
105 105SQL>
分为左连接和右连接
例:
SQL> select * from a1;BBB
----------
101
102
103
104
105SQL> select * from a2;BBB CCC
---------- --------------------
101
102
105SQL> select * from a1,a2 where a1.bbb(+)=a2.bbb;BBB BBB CCC
---------- ---------- --------------------
101 101
102 102
105 105SQL> select * from a1,a2 where a1.bbb=a2.bbb(+);BBB BBB CCC
---------- ---------- --------------------
101 101
102 102
103
104
105 105SQL>
解决方案 »
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