mysql - 我的目标是合并这两个查询。我在以单独的方式执行时存在差异

Question

Image1 Image帮我合并这两个给定的查询

SELECT DISTINCT vehicle_no FROM petty_cash;

SELECT COUNT(variation) as bal FROM petty_cash WHERE variation<0;

提前致谢。

Answer 1

I'm not sure about your output but i can combine those 2 queries as below.

SELECT DISTINCT vehicle_no, COUNT(variation) as bal FROM petty_cash WHERE variation < 0;

Answer 2

您可以使用案例来获得您想要的结果，

喜欢，

SELECT DISTINCT vehicle_no,CASE WHEN variation==0 THEN 'HIDE ROW' END FROM petty_cash;

执行此查询后，您可以获得具有 HIDE ROW 值且变化为零的车辆数量。在“HIDE ROW”的位置，您可以设置 0 或 1 以便您理解。

我希望这能帮到您。

Answer 3

您想在一个查询中执行两条语句吗？答案是肯定的那么它

SELECT  (
  SELECT DISTINCT vehicle_no FROM petty_cash       
) AS firstStatment,
(
 SELECT COUNT(variation) as bal FROM petty_cash WHERE variation<0
) AS secondStatment