在mysql4中可以
SELECT ....
UNION [ALL]
SELECT ....
[UNION
SELECT ...]
在mysql4以下版本只能这样了
CREATE TEMPORARY TABLE tmp
SELECT field1_index, field2_index FROM test_table WHERE field1_index = '1';
INSERT INTO tmp
SELECT field1_index, field2_index FROM test_table WHERE field2_index = '1';
SELECT * from tmp;
DROP TABLE tmp;
SELECT ....
UNION [ALL]
SELECT ....
[UNION
SELECT ...]
在mysql4以下版本只能这样了
CREATE TEMPORARY TABLE tmp
SELECT field1_index, field2_index FROM test_table WHERE field1_index = '1';
INSERT INTO tmp
SELECT field1_index, field2_index FROM test_table WHERE field2_index = '1';
SELECT * from tmp;
DROP TABLE tmp;
要看你的具体需求,你最好把你的目地表达的更清楚一点,比如你要把A表的某某字段和B表的某某字段合到一个结果集中,A表和B表之间的关系。
id row1 row2 row3 row4 row5table2
id r1 r2 r3 r4其中table1.row5和table2.r4是一样的,查询要求是row5和r4都为5,而且要得到row1,row2,row3,r2,r3的值,请问这个SQL怎么写呢?