子查询中的group_concat

Question

select GROUP_CONCAT(DISTINCT tbl1.logid)  ,
(

    SELECT COUNT( DISTINCT tbl2.client_id ) 
    FROM tbl_client tbl2

    WHERE tbl2.con_id
    IN ( GROUP_CONCAT(DISTINCT tbl1.logid) ) 


) as PC2,

from tbl_table tbl1;

i try to assign an alias of GROUP_CONCAT(DISTINCT tbl1.logid) and place it in the value inside the IN() but still it doesn't work out

the parent query returns something like 12,34,3,56 and that i want to use in the IN function

this not actually the whole case, but i just want to figure this out,

Answer 1

You cannot use the output of GROUP_CONCAT for IN() as it is returning a string. Use the result of a subquery for IN().

select GROUP_CONCAT(DISTINCT tbl1.logid)  ,
(

SELECT COUNT( DISTINCT tbl2.client_id ) 
FROM tbl_client tbl2

WHERE tbl2.con_id
IN ( SELECT logid from tbl_table ) 


) 

as PC2,

from tbl_table tbl1;