具有计算表达式的子查询的条件表达式中的数据类型不匹配

Question

I am trying to create a SQL subquery in MS Access. Getting "type mismatch in expression
criteria" error message.

Subquery is

SELECT *
  (SELECT Locs_Eq.Locs_Eq 
   FROM Locs_Eq 
   WHERE Query6.StDeExtrREF=CStr(Locs_Eq.Full_VendSN)
  ) AS Loc_1
FROM Query6

The variable DeExtrREF from Query6 is as follows:

 IIF(PDetail.VeName="Siem" AND [DeExtr1]="Contr REF#",
     TRIM(MID (PDetail.Desc, (InStr([PDetail.Desc],":")+1), LEN(PDetail.Desc))),
     TRIM(MID (PDetail.Desc, (InStr([PDetail.Desc],":")+1), LEN(PDetail.Desc))) 
    ) AS DeExtrREF

I tried adding CStr to the variables, still receive the error message. Please help.

Answer 1

I will assume that you have a comma after SELECT * on the first line. If not, change this first and see if this helps.

I am not certain, but it is probably a null-related error; Add this to a module in your access app:

public function is_null(val as variant, rplc as string) as string
    if isnull(val) then
        is_null = rplc
    else
        is_null = cstr(val)
    end if
end function

then change your query to use this, as follows:

SELECT q.*,
  (SELECT l.Locs_Eq 
   FROM Locs_Eq l 
   WHERE is_null(q.StDeExtrREF, "") = CStr(is_null(l.Full_VendSN, ""))
  ) AS Loc_1
FROM Query6 q

Hope this helps. I alias tables and queries automatically, but as a general rule you're more likely to get help here if your queries are not too difficult to understand.