sql如何按条件添加值并放入特定列

Question

这是表和表中的数据。

桌子：

id |value_total|value_1|value_2|value_3|value_4 
1  | 100       | 50    | 0     | 0     | 50
2  | 200       | 0     | 150   | 50    | 0
3  | 300       | 100   | 200   | 0     | 0
4  | 400       | 100   | 200   | 0     | 100

我需要包含以下数据的表格。

愿望结果：

id |value_total|value_1|value_2|value_3|value_4 
1  | 100       | 0     | 0     | 0     | 100
2  | 200       | 0     | 0     | 200   | 0
3  | 300       | 0     | 300   | 0     | 0
4  | 400       | 0     | 0     | 0     | 400

Answer 1

您想将总值放在最后一个非零列中吗？

select id, value_total,
       (case when value_2 = 0 and value_3 = 0 and value_4 = 0 and value_1 > 0
             then value_total else 0
        end) as value_1,
       (case when value_3 = 0 and value_4 = 0 and value_2 > 0
             then value_total else 0
        end) as value_2,
       (case when value_4 = 0 and value_3 > 0
             then value_total else 0
        end) as value_3,
       (case when value_4 > 0 then value_total else 0 end)
from t;

Answer 2

这种情况有很多方法，下面提到了其中一种方法，请看一看。

UPDATE TABLE
SET value_1 = 0
    ,value_2 = CASE 
        WHEN id = 3
            THEN 300
        ELSE 0
        END
    ,value_3 = CASE 
        WHEN id = 2
            THEN 200
        ELSE 0
        END
    ,value_4 = CASE 
        WHEN id = 1
            THEN 100
        WHEN id = 4
            THEN 400
        ELSE 0
        END