Problem with LIMIT & IN/ALL/ANY/SOME subquery

Question

I have this query:

SELECT count(cp.CxID) as intSmokers 
FROM CustPrimarySmoking cp 
JOIN Customer c ON cp.CxID = c.CustomerID 
WHERE 
cp.CxID IN (SELECT CxID         


        

Answer 1

This is how you need to proceed. See the example that I've worked out.

mysql> select * from test;
+------+-------+
| id   | name  |
+------+-------+
|    1 | name1 |
|    2 | name2 |
|    3 | name3 |
|    4 | name4 |
+------+-------+
4 rows in set (0.00 sec)

mysql> select * from test1;
+------+------+--------+
| id   | tid  | name2  |
+------+------+--------+
|    1 |    2 | name11 |
|    2 |    3 | name12 |
|    3 |    4 | name13 |
+------+------+--------+
3 rows in set (0.00 sec)

mysql> select
    ->  t1.name
    -> from
    ->  test t1
    -> join
    ->  test1 t2 on t2.tid = t1.id
    -> join
    ->  (select id from test where id <4 limit 3) as tempt on tempt.id = t1.id;
+-------+
| name  |
+-------+
| name2 |
| name3 |
+-------+
2 rows in set (0.00 sec)

Hope this helps.