如何将同一数据库中三个表的三个字段数据相加

Question

我有一张名为Sound的表

id name hit

• 100 sam 12
• 101 zad 10

和其他表格像这样抨击SoundK

id name hit

• 102 qwe 12
• 103 rty 10

和其他表格像这样的SoundD

id name hit

• 104 asd 12
• 105 xcv 10

所以如何计算所有三个表Sound + SoundK + SoundD

的字段（命中）为总数

提前致谢

RGDS for All

Answer 1

以通用方式，您可以将三个表合并在一起，因为它们共享相同的数据，然后进行求和。

select sum(hit)
from (
    select hit
    from Sound
    union
    select hit
    from SoundK
    union
    select hit
    from SoundD
)

Answer 2

SELECT SUM (soundsum) FROM (
SELECT SUM(hit) AS SoundSum FROM Sound AS s
UNION ALL
SELECT SUM(hit) AS SoundSum FROM SoundK AS s
UNION ALL
SELECT SUM(hit) AS SoundSum FROM SoundD AS s
) X