MySQL--开发技巧(一)

Inner Join:

Left Outer Join:

Right Outer Join:

Full Join:

 

Cross Join：

SELECT t1.attrs ,t2.attrs FROM t1 CROSS JOIN t2

 

使用Join更新表：

UPDATE table1 SET  attr2  WHERE  attr1  IN (SELECT table2.attr1 FROM table1 INNER JOIN table2 ON table1.attr1 =table2.attr1 )