1. update a set a.counter=a.counter+b.counter from a,b where a.name=b.name
2、a和c1/c2/c3……/cn等n个表(n=[a-z0-9])。每个表内都有字段name、counter。其中name的关系为a.name=c1.name+c2.name+……+cn.name等所有分表的name并集。想遍历更新a,使a.counter=a.counter+cn.counter where a.name=cn.name 。是否只能如是更新: 定义一个数组$arr=array("0","1","2",…,"9","a",…,"z"),然后for循环,运行语句为 "update a set a.counter=a.counter+c".$arr[$i].".counter where a.name=c".$arr[$i].".name
update a set a.counter=a.counter+b.counter from a,b where a.name=b.name
"update a set a.counter=a.counter+c".$arr[$i].".counter where a.name=c".$arr[$i].".name