Field name confusion - sql

Question

rs2.FindFirst "[aniin] ='" & strTemp & "'"
aniin being an alias from the SQL within the function.
also tried ...
rs2.FindFirst (niin = newdata)
is my attempt to isolate the field name niin from the record value in the form from the one in the strSQL2. All my attempts have failed. I am trying to make sure that what the user typed in does match the list from the SQL string.
Private Function IsPartOfAEL(newdata) As Boolean
On Error GoTo ErrTrap
Dim db2 As DAO.Database
Dim rs2 As DAO.Recordset
Dim strTemp As String
strSQL2 = "SELECT tbl_ael_parts.master_ael_id, tbl_master_niin.niin as aniin " & vbCrLf & _
"FROM tbl_master_niin INNER JOIN tbl_ael_parts ON tbl_master_niin.master_niin_id = tbl_ael_parts.master_niin_id " & vbCrLf & _
"WHERE (((tbl_ael_parts.master_ael_id)= " & Forms!frm_qry_niin_local!master_ael_id & "));"
Set db2 = CurrentDb
Set rs2 = db2.OpenRecordset(strSQL2)
strTemp = newdata
If rs2.RecordCount <> 0 Then
rs2.FindFirst "[aniin] ='" & strTemp & "'"
If rs2.NoMatch Then
IsPartOfAEL = False
Else
IsPartOfAEL = True
End If
Else
MsgBox "Query Returned Zero Records", vbCritical
Exit Function
End If
rs.Close
Set rs2 = Nothing
Set db2 = Nothing
ExitHere:
Exit Function
ErrTrap:
MsgBox Err.description
Resume ExitHere
End Function

Answer 1

First: You should never include a constant like vbCrLf when building a query string. The query parser doesn't care if there's a linefeed, and in fact this can sometimes cause issues.
Your code seems to do nothing more that verify whether the value in newdata exists in the tbl_ael_parts and is associated with the value master_ael_id value currently showing on frm_qry_niin_local. If so, then just use DCount, or use this for your query:
strSQL2 = "SELECT tbl_ael_parts.master_ael_id INNER JOIN tbl_ael_parts ON
tbl_master_niin.master_niin_id = tbl_ael_parts.master_niin_id WHERE (((tbl_ael_parts.master_ael_id)=
" & Forms!frm_qry_niin_local!master_ael_id & ") AND niin=" & newdata & ");"
Dim rst As DAO.Recordset
Set rst = currentdb.OPenrecordset(strsql2)
If (rst.EOF and rst.BOF) Then
' no records returned
Else
' records found
End If
If niin is a Text field:
strSQL2 = "SELECT tbl_ael_parts.master_ael_id INNER JOIN tbl_ael_parts ON
tbl_master_niin.master_niin_id = tbl_ael_parts.master_niin_id WHERE (((tbl_ael_parts.master_ael_id)=
" & Forms!frm_qry_niin_local!master_ael_id & ") AND (niin='" & newdata & "'));"
If both niin and master_ael_id are Text fields:
strSQL2 = "SELECT tbl_ael_parts.master_ael_id INNER JOIN tbl_ael_parts ON
tbl_master_niin.master_niin_id = tbl_ael_parts.master_niin_id WHERE (((tbl_ael_parts.master_ael_id)=
'" & Forms!frm_qry_niin_local!master_ael_id & "') AND (niin='" & newdata & "'));"