Joining two tables in a select

Question

I have two tables:

TABLE 1
ID   VALUE   
1    ABC
2    DEF
3    GHI
4    JKL
5    XYZ

TABLE 2
ID  T1_ID  VALUE 
1   1      A
2   1      B
3   2      A
4   3            


        

Answer 1

Tadaaah! Without a subquery.

select distinct
  t1.*
from
  Table1 t1
  inner join Table2 t2a on t2a.t1_ID = t1.ID and t2a.VALUE = 'A'
  inner join Table2 t2b on t2b.t1_ID = t1.ID and t2b.VALUE = 'B'

Answer 2

SELECT t1.ID,
       t1.VALUE
FROM   Table1 t1
       JOIN Table2 t2
         ON t1.ID = t2.T1_ID
WHERE  t2.VALUE IN ( 'A', 'B' )
GROUP  BY t1.ID,
          t1.VALUE
HAVING COUNT(DISTINCT t2.VALUE) = 2