Multiple Join not working on two string attributes

I have the following issue:

I have several tables in my Database, in order to check for a specific criteria I have to join several tables, where I use the following statement:

SELECT *
    FROM (SELECT * FROM (((((((((SELECT * FROM table1 WHERE tab1_id = 1)  AS A
            INNER JOIN (SELECT * FROM table2 WHERE tab2_variable IS NOT NULL) AS B
                ON A.variable = B.variable)
            INNER JOIN (SELECT table3.*, IIF(year='XXXX', 0, 1) AS flag FROM table3) AS C
                ON A.h_name = C.h_name)
            INNER JOIN (SELECT * FROM table4 WHERE s_flag = 0) AS D
                ON C.v_type = D.v_type)
            INNER JOIN table5
                ON C.ng_type = table5.ng_type)
            INNER JOIN table6
                ON C.part = table6.part)
            INNER JOIN table7
                ON C.ifg = table7.ifg)
            INNER JOIN table8
                ON C.v_type = table8.v_type AND C.ng_typ = table8.ng_typ AND C.ntr_flag = table8.ntr_flag)
            INNER JOIN table9
                ON table8.ifg_sii_id = table9.ifg_sii_id)) AS F
        LEFT JOIN table10
            ON F.risk = table10.risk AND C.v_type = table10.v_type
                AND F.series = table10.series

This statement fails. But when I remove one the following two join-conditions in the last Left JOIN, it works as intended:

F.risk = table10.risk and/or C.v_type = table10.v_type

They are both of type CHAR, whereas series is type TINYINT, I guess it has something to do with joining on multiple conditions with strings, but I’m not able to find a workaround, any ideas?

Answer

according to your current SQL, Table C is not visible as it’s a sub query within F. instead of C.v_type you need to use F.c_v_type and the c_v_type field must come from C table like. select v_type as c_v_type from table3... as C