SQL con parametros

query1.close;
query1.SQL.Clear;
query1.SQL.add('insert into query1 (fecha, importeT, importeE, concepto, empleado, total) values (:fecha, :importeT, :importeE, :concepto, :empleado, :total)');
query1.ParamByName('fecha').Value:=Date;
query1.ParamByName('importeE').Value:=strtofloat(StringGrid1.Cells[2,i]);
query1.ParamByName('importeT').Value:=strtofloat('0');
query1.ParamByName('concepto').Value:=StringGrid1.Cells[0,i];
query1.ParamByName('empleado').Value:=StringGrid1.Cells[1,i];
query1.ParamByName('total').Value:=strtofloat(StringGrid1.Cells[2,i]);
query1.ExecSQL;