表的连接

表的连接有三种

1. 内连接
   
   • 在MySQL中，JOIN,CROSS JOIN 和 INNER JOIN 是等价的。
2. 左外连接 LEFT [OUTER] JOIN
3. 右外连接 RIGHT [OUTER] JOIN

语法结构

table_reference {[INNER|CROSS] JOIN | {LEFT|RIGHT}[OUTER] JOIN } table_reference ON conditional_expr

mysql> UPDATE tdb_goods AS g INNER JOIN tdb_goods_brands AS b ON g.brand_name = b.brand_name    -> SET g.brand_name = b.brand_id;