查询适用于sql server management studio 2008但不适用于delphi

Question

我正在开发一个程序来使用sql server更新delphi 7中表中的某些字段.程序是这样的:

sql := 'UPDATE tb_dt_contract SET '
      +' id_schedule = '+quotedstr(label_id_schedule.Caption)
      +',start_date = '+quotedstr(formatdatetime('mm/dd/yyyy',DateTime_start.Date))
      +',finish_date = '+quotedstr(formatdatetime('mm/dd/yyyy',DateTime_finish.Date))
      +',contract_location = '+quotedstr(uppercase(Edit_location.Text))
      +',sign_date = '+quotedstr(formatdatetime('mm/dd/yyyy',DateTime_sign.Date))
      +' WHERE id = '+quotedstr(label_id.Caption);
ADOQuery1.Close;
ADOQuery1.SQL.Text := sql;
ADOQuery1.ExecSQL;

当我运行程序时,它给了我一个错误:'''''附近的语法不正确.但是当我使用showmessage查看查询并在sql server management 2008中运行它时,它工作正常.

然后我尝试将查询拆分成这样的部分:

SQL := 'UPDATE tb_dt_contract SET '
      +' id_schedule = '+QUOTEDSTR(label_id_schedule.CAPTION)
      +' WHERE id = '+quotedstr(label_id.Caption);
ADOQuery1.Close;
ADOQuery1.SQL.Text := sql;
ADOQuery1.ExecSQL;

SQL := 'UPDATE tb_dt_contract SET '
      +' start_date = '+quotedstr(formatdatetime('mm/dd/yyyy',DateTime_start.Date))
      +' WHERE id = '+quotedstr(label_id.Caption);
ADOQuery1.Close;
ADOQuery1.SQL.Text := sql;
ADOQuery1.ExecSQL;

SQL := 'UPDATE tb_dt_contract SET '
      +' finish_date = '+quotedstr(formatdatetime('mm/dd/yyyy',DateTime_finish.Date))
      +' WHERE id = '+quotedstr(label_id.Caption);
ADOQuery1.Close;
ADOQuery1.SQL.Text := sql;
ADOQuery1.ExecSQL;

SQL := 'UPDATE tb_dt_contract SET '
      +' contract_location = '+quotedstr(uppercase(edit_location.Text))
      +' WHERE id = '+quotedstr(label_id.Caption);
ADOQuery1.Close;
ADOQuery1.SQL.Text := sql;
ADOQuery1.ExecSQL;

SQL := 'UPDATE tb_dt_contract SET '
      +' sign_date = '+quotedstr(formatdatetime('mm/dd/yyyy',DateTime_sign.Date))
      +' WHERE id = '+quotedstr(label_id.Caption);
ADOQuery1.Close;
ADOQuery1.SQL.Text := sql;
ADOQuery1.ExecSQL;

然后我发现它只在更新日期类型字段时触发错误.我已经开发了其他程序来使用类似的查询更新不同的表,它工作正常..我尝试关闭项目并重新打开它但它仍然给我错误消息.请告诉我应该怎么做..

Answer 1

要避免转换并创建数据库独立的保存查询,您应该使用参数,如果多次使用,也可以加快操作速度.

  Adoquery1.SQL.Text := 'UPDATE tb_dt_contract SET finish_date=:df where WHERE id =:id';
  // in some cases it may be necessary to add  the three comented lines
  //Adoquery1.Parameters.ParseSQL(Adoquery1.SQL.Text,true);
  //Adoquery1.Parameters.ParamByName('df').DataType := ftDateTime;
  //Adoquery1.Parameters.ParamByName('id').DataType := ftInteger;
  Adoquery1.Parameters.ParamByName('df').Value :=DateTime_finish.Date;
  Adoquery1.Parameters.ParamByName('ID').Value :=StrToInt(label_id.Caption);
  Adoquery1.ExecSQL;