Property HasRows in C #

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Property HasRows in C #

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#1 by (1 votes)

-1

I'm doing SELECT mysql with inner join within my C # application

          MySqlCommand _comandoDados = new MySqlCommand(String.Format(
              "select EMGroot.id, EMGroot.lbs_net, EMGroot.lbs_gross_aai, EMGroot.price_brazil, sum(AAIest.qtd_venda) " +
              "from eaglemo4_eaglemotorsg.tb_products_root EMGroot " +
              "inner join eaglemo4_americai.tb_estoque AAIest " +
              "on AAIest.id_produto = EMGroot.id " +
              "where EMGroot.manupart = '" + txtManuPartInserir.Text + "'"), conexao_aai);

        MySqlDataReader Open_readerteste = _comandoDados.ExecuteReader();
        Open_readerteste.Read();

After getting a Reader I should throw the data to some fields, but for there to be no "DATA IS NULL" error, I create the condition HasRows :

   if(Open_readerteste.HasRows)
   {
     root_id = Open_readerteste.GetInt16(0)
     ....
   }

but the result of the condition is always being TRUE even when there is no rows . Can anyone tell me whether because of inner join reader always considers data in the command? or why HasRows always be true?

=================
Updating my question; You will find that HasRows is always true because of the sum(AAIest.qtd_venda) field search. With the sum () tool HasRows will always indicate that there are rows within the dataReader.

Is there a way to work this out?

mysql c#

asked by anonymous 20.07.2018 / 20:20

1 answer

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score 1 · Accepted Answer

Try to include the having clause to guarantee rows only when SUM is greater than zero or some other counter is greater than zero.


   "select EMGroot.id, EMGroot.lbs_net, EMGroot.lbs_gross_aai, EMGroot.price_brazil, sum(AAIest.qtd_venda) " +
              "from eaglemo4_eaglemotorsg.tb_products_root EMGroot " +
              "inner join eaglemo4_americai.tb_estoque AAIest " +
              "on AAIest.id_produto = EMGroot.id " +
              "where EMGroot.manupart = '" + txtManuPartInserir.Text + "'
GROUP BY EMGroot.id, EMGroot.lbs_net, EMGroot.lbs_gross_aai, EMGroot.price_brazil
HAVING sum(AAIest.qtd_venda) > 0
"