mysql常用语句

1、用户A表的某一列更新B表的某一列
eg:用t2表的c_account_id替换t1表的c_counter_part_id字段

update t_invest_account_cashflow t1 set
 t1.c_counter_part_id=(select t2.c_account_id from
 t_invest_account t2 where
 t1.c_invest_account_id=t2.c_invest_account_id )

2、产生自增编号
rowNum将从1开始自增

set @row=0;
select c_account_cashflow_id ,@row:=@row+1 rowNum 
 from t_account_cashflow where
 c_account_cashflow_id ;