Question
I have a table structure as under:
ID A B
-- --- -----
1 a a1
2 b b1
3 a a2
4 c a1
5 b b2
I want such values from column A, who are related to ALL the values of B in a list.
For Example:
I have a list of A's:
{a1,a2}
Output should be a,
c is NOT returned in the result because it is related to a1 only and not
a2.
Is there a way to get this result by a SQL query?
Edited
It should work in this special case:
ID A B
-- --- -----
1 a a1
2 b b1
3 a a2
4 c a1
5 b b2
6 c a3
7 c a2
Now c is also related to a2 and a3, but it should NOT be returned
because for being a part of result, c should be related to exactly a1 AND
a2
But if I query as follows:
SELECT A
FROM table_name
WHERE B IN ( 'a1', 'a2' ) -- The items in the list
GROUP BY A
HAVING COUNT( DISTINCT b ) = 2;
It returns c too.
Answer
Oracle Setup :
CREATE TABLE table_name ( ID, A, B ) AS
SELECT 1, 'a', 'a1' FROM DUAL UNION ALL
SELECT 2, 'b', 'b1' FROM DUAL UNION ALL
SELECT 3, 'a', 'a2' FROM DUAL UNION ALL
SELECT 4, 'c', 'a1' FROM DUAL UNION ALL
SELECT 5, 'b', 'b2' FROM DUAL;
Query - UseGROUP BY and COUNT( DISTINCT ... ):
SELECT A
FROM table_name
WHERE B IN ( 'a1', 'a2' ) -- The items in the list
GROUP BY A
HAVING COUNT( DISTINCT b ) = 2; -- The number of items in the list
Output :
A
-
a
Query - Passing the list dynamically :
CREATE OR REPLACE TYPE stringlist IS TABLE OF VARCHAR2(10);
/
SELECT A
FROM table_name
WHERE B MEMBER OF :your_list
GROUP BY A
HAVING COUNT( DISTINCT B ) = CARDINALITY( :your_list );
Where the bind variable:your_list is of type stringlist.
If the list is passed as a delimited string then you can use any of the techniques in the [Splitting delimited strings](https://web.archive.org/web/20170914140540/https://stackoverflow.com/documentation/oracle/1968/splitting- delimited-strings) documentation page to separate it. There is a simple PL/SQL function that would return it as a collection that could be plugged into the above query.
Update :
SELECT A
FROM table_name
GROUP BY A
HAVING COUNT( DISTINCT CASE WHEN b IN ( 'a1', 'a2' ) THEN b END ) = 2
AND COUNT( DISTINCT CASE WHEN b NOT IN ( 'a1', 'a2' ) THEN b END ) = 0;
or
SELECT A
FROM table_name
GROUP BY A
HAVING COUNT( DISTINCT CASE WHEN b MEMBER OF :your_list THEN b END ) = CARDINALITY( :your_list )
AND COUNT( DISTINCT CASE WHEN b NOT MEMBER OF :your_list THEN b END ) = 0;
