複製列值插入到另一匹配ID

Question

我有兩個表

t1 
     id | value 
     1 | - 
     2 | - 
t2 
     parent_id | p_value 
     1   | 254 
     2   | 124 

我想列p_value從T2複製到T1，其中parent_id = id

Answer 1

update t1, t2 set t1.value = t2.p_value where t1.id=t2.parent_id 

Answer 2

試試這個

update t1 join t2 on t2.parent_id= t1.id set t1.value = t2.p_value 

Answer 3

試試這個：

Update t1, t2 set t1.value = t2.p_value where t1.id = t2.parent_id;