public DataTable ventastotales()
{
String sql = "select case tipodoc when 'BOL' then 'BOLETAS DE VENTA when" +
"'FAC' then 'FACTURAS' end as 'TIPO DOC',numerodocumento as " +
"'NUM DOC',fechaventa as 'FECHA VENTA',igv as IGV,subtotal as SUBTOTAL" +
"from tb_ventas";
BDConnect conexion = new BDConnect();
return(conexion.ejecutarconsulta(sql));
}