用其他表值更新表

Question

我有2个表department_referance和department中的代码与department表中的department_string_id相等的department。

department_referance //table
id code   sl_flag
    DD01  1 

department //table
department_id department_string_id  sl_flag
               DD01

我想从department_referance获取sl_flag值，并更新部门表的sl_flag中的值。

update sl_flag='(SELECT a.sl_flag FROM department_referance a inner JOIN department b on a.code=b.department_string_id)'

Answer 1

您可以通过JOIN （ JOIN ）两个表来更新它。

询问

update `department ` t1
join `department_referance ` t2
on t1.`code` = t2.`department_string_id`
set t1.`sl_flag` = t2.`sl_flag`;

Answer 2

您可以使用此查询

UPDATE department d 
join department_referance 
dr on dr.code = d.department_string_id 
set d.sl_flag = dr.sl_flag