sql多表级联更新update的用法举例

两个表级联更新(update)的例子。

-- 两个表的级联更新
update customers a
set    city_name=(select b.city_name from tmp_cust_city b where b.customer_id=a.customer_id)
where  exists (select 1
                  from   tmp_cust_city b
                  where  b.customer_id=a.customer_id
)

-- update 多于二个表
update customers a 
set    (city_name,customer_type)=(select b.city_name,b.customer_type
               from   tmp_cust_city b
                 where  b.customer_id=a.customer_id)
where  exists (select 1
  from   tmp_cust_city b
  where  b.customer_id=a.customer_id
)
--by 脚本学堂 http://www.jb200.com