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分享想问一下,(+)是什么意思??
看到一个sql语句
select * from a,b where a.id(+) = b.id,这是什么意思啊??
select * from a,b where a.id(+) = b.id,这是什么意思啊??
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smallcrocodile 2003-06-30
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连接
silverfoxes 2003-06-30
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明白了,谢谢
bzszp 2003-06-30
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外连接
SQL> select * from a1;
BBB
----------
101
102
103
104
105
SQL> select * from a2;
BBB CCC
---------- --------------------
101
102
105
SQL> select * from a1,a2 where a1.bbb(+)=a2.bbb;
BBB BBB CCC
---------- ---------- --------------------
101 101
102 102
105 105
SQL> select * from a1,a2 where a1.bbb=a2.bbb(+);
BBB BBB CCC
---------- ---------- --------------------
101 101
102 102
103
104
105 105
SQL>
SQL> select * from a1;
BBB
----------
101
102
103
104
105
SQL> select * from a2;
BBB CCC
---------- --------------------
101
102
105
SQL> select * from a1,a2 where a1.bbb(+)=a2.bbb;
BBB BBB CCC
---------- ---------- --------------------
101 101
102 102
105 105
SQL> select * from a1,a2 where a1.bbb=a2.bbb(+);
BBB BBB CCC
---------- ---------- --------------------
101 101
102 102
103
104
105 105
SQL>
