sql从3个不同的表中提取相同的列

Question

Hi i have 3 tables i want to extract same columns from 3 tables is this better way to write Select query.

select * from 
(
select col1,
select id1 from testid1 where name=pnrtable1.name,
col3 from table1  
union all  
select coltab1,
select newid2 from testid2 where name=pnrtable2.name,
coltab3 from table2  
union all  
select namecol1,
select id3 from testid3 where name=pnrtable3.name,
namecol3 from table3  
)

Answer 1

Not sure but I think you are after something like this....

select * from 
(
select t1.col1, t2.id1 , t1.col3 from table1  t1 
                                 INNER JOIN testid1 t2 ON t1.name = t2.name
union all  
select t1.coltab1, t2.newid2, t1.coltab3 from testid2 t1 
                                         INNER JOIN table2 t2 ON t1.name=t2.name
union all  
select t1.namecol1, t2.id3, t1.namecol3 from testid3 t1 
                                       INNER JOIN table3 t2 ON t1.name=t2.name
) A