现有1个表和多个表有关联,属于1对多关系。
T1
id , tbId
1 , 1
2 , 2
3 , 4
4 , 5这个tbId的值分对应1:T2 , 2:T2 , 4:T3 ,5:T4
T2, T3, T4 的表结构是
tid, name现在要显示的结果是
id, tbId, name
1 , 1 A
2 , 2 B
3 , 4 C
4 , 5 D请问这样的语句如何些?数据库MYSQL
T1
id , tbId
1 , 1
2 , 2
3 , 4
4 , 5这个tbId的值分对应1:T2 , 2:T2 , 4:T3 ,5:T4
T2, T3, T4 的表结构是
tid, name现在要显示的结果是
id, tbId, name
1 , 1 A
2 , 2 B
3 , 4 C
4 , 5 D请问这样的语句如何些?数据库MYSQL
From T1 , (
select 1 as tbId , tid,name from T2
Union all
select 2 as tbId , tid,name from T3
Union all
select 3 as tbId , tid,name from T4
Union all
select 4 as tbId , tid,name from T5
) tx
Where t1. tbId=tx. tbId and t1. Id=tx. tid
select * from T2
Union all
select * from T3
Union all
select * from T4
Union all
select * from T5
) b on a. tbId=b.tId