“type mismatch expecting AutoInc actual LongWord” on FDQuery (Delphi XE6)

Question

We use Delphi XE6 the component with error is a TFDQuery in MySQL 4.1.

When I try to open the Query using a group the FDQuery show:

type mismatch expecting AutoInc actual LongWord

In the Field Editor the field is correct,it shows AutoInc but the error always appears, if I remove the group by on query the error stop but the results is wrong and when I remove all fields of Field Editor and try again, work correctly.

I tried to insert a field manually on Field Editor as an Integer field, but it didn't work either.

The field with error (NUMBOLE) in my table is an Integer field, AutoInc (primary key from tabbolvenda)

  FDQuery1.Close;
  FDQuery1.SQL.Clear;
  FDQuery1.SQL.Add('select');
  FDQuery1.SQL.Add('b.NUMVENDA,');
  FDQuery1.SQL.Add('a.DATAVENDA,');
  FDQuery1.SQL.Add('b.NUMBOLE,');
  FDQuery1.SQL.Add('b.PARCELAS,');
  FDQuery1.SQL.Add('a.CODCLIENTE,');
  FDQuery1.SQL.Add('a.NOMECLIENTE,');
  FDQuery1.SQL.Add('b.DATAVTO,');
  FDQuery1.SQL.Add('a.MONTANTE,');
  FDQuery1.SQL.Add('b.DATAPTO,');
  FDQuery1.SQL.Add('if(b.EMABERTO = ''True'', ''Sim'',''Não'') as EMABERTO,');
  FDQuery1.SQL.Add('a.CUSTOVENDA,');
  FDQuery1.SQL.Add('a.LUCROVENDA,');
  FDQuery1.SQL.Add('a.COMISSAO');
  FDQuery1.SQL.Add('from tabvendas a inner join tabbolvenda b');
  FDQuery1.SQL.Add('on a.NUMVENDA = b.NUMVENDA');
  FDQuery1.SQL.Add('group by b.NUMVENDA order by b.NUMVENDA'); <--- if I remove this group by it works
  FDQuery1.Open;

Is there any property on FDQuery that it makes this error disappear? When my project use to be on Delphi 6 with Zeos Query, the same select doesn't show any error message. It happens only on FDQuery.

MySQL changes an auto-inc column data type when it is in SELECT list with and without GROUP BY. Do you created persistent fields when query was with GROUP BY ? — da-soft

Roman Marusyk Roman Marusyk · Accepted Answer · 2015-09-01T13:32:20

Number of fields in select have to be equal the number of fields in group by if you not use aggregate functions.
From docs:

SELECT expression1, expression2, ... expression_n, 
       aggregate_function (aggregate_expression)
FROM tables
WHERE conditions
GROUP BY expression1, expression2, ... expression_n;

where expression1, expression2, ... expression_n - Expressions that are not encapsulated within an aggregate function and must be included in the GROUP BY Clause at the end of the SQL statement.

“type mismatch expecting AutoInc actual LongWord” on FDQuery (Delphi XE6)

1 Answers