php - 在sql中添加两列的值

Question

我有一个类似于下面的代码

SELECT SUM(points_1) AS total_points_1, SUM(points_2) AS total_points_2,

       total_points_1 +
       CASE 
         WHEN total_points_1 BETWEEN 50 AND 100 THEN 50
         WHEN total_points_1 BETWEEN 100 AND 200 THEN 100
         WHEN total_points_1 BETWEEN 200 AND 300 THEN 200
         WHEN total_points_1 BETWEEN 300 AND 400 THEN 300
         ELSE 500
       END AS another_row_1,

       total_points_2 +
       CASE 
         WHEN total_points_2 BETWEEN 50 AND 100 THEN 50
         WHEN total_points_2 BETWEEN 100 AND 200 THEN 100
         WHEN total_points_2 BETWEEN 200 AND 300 THEN 200
         WHEN total_points_2 BETWEEN 300 AND 400 THEN 300
         ELSE 500
       END AS another_row_2,

FROM  `table`

我的目标是添加 another_row_1 和 another_row_2 的结果

我尝试在 END AS another_row_2, 之后执行下面的行，但没有成功

SUM(another_row_1 + another_row_2) AS total_sum

Answer 1

首先，为了减少困惑并提高可维护性，我建议将点重新计算逻辑(用 CASE 实现的逻辑)包装到一个函数中

CREATE FUNCTION add_points(_points INT)
RETURNS INT
RETURN 
  _points + 
  CASE 
    WHEN _points BETWEEN  50 AND  99 THEN 50
    WHEN _points BETWEEN 100 AND 199 THEN 100
    WHEN _points BETWEEN 200 AND 299 THEN 200
    WHEN _points BETWEEN 300 AND 399 THEN 300
    ELSE 500
  END;

注意:您可能需要将数据类型从 INT 更改为 DECIMAL(n,m)(根据您的实际数据类型列 points_1 和 points_2)

现在查询看起来像

SELECT total_points_1,
       total_points_2,
       another_total_1,
       another_total_2,
       another_total_1 + another_total_2 total_sum
  FROM
(
  SELECT SUM(points_1) total_points_1, 
         SUM(points_2) total_points_2,
         add_points(SUM(points_1)) another_total_1,
         add_points(SUM(points_2)) another_total_2
    FROM table1
) q

示例输出:

| TOTAL_POINTS_1 | TOTAL_POINTS_2 | ANOTHER_TOTAL_1 | ANOTHER_TOTAL_2 | TOTAL_SUM ||----------------|----------------|-----------------|-----------------|-----------||            165 |            386 |             265 |             686 |       951 |

这是 SQLFiddle 演示