Question

我有一个名为tbl_populations的表，其中包含以下字段：

pk_populationid,residence,value,aspect,gender,fk_tbl_states_stateid

我正在尝试计算两个方面的行差异

例如。

SELECT fk_tbl_states_stateid, value - (
SELECT value
FROM tbl_populations
WHERE fk_tbl_states_stateid = '16'
AND fk_tbl_districts_districtid = '0'
AND residence = '0'
AND gender = '0'
AND aspect = '2' ) AS difference
FROM tbl_populations
WHERE fk_tbl_states_stateid = '16'
AND fk_tbl_districts_districtid = '0'
AND residence = '0'
AND gender = '0'
AND aspect = '1'

它正常工作，因为它返回一行

为了获取我想要检索所有性别值的多个数据，我已从条件中删除了性别。

SELECT fk_tbl_states_stateid,gender, value - (
SELECT value
FROM tbl_populations
WHERE fk_tbl_states_stateid = '16'
AND fk_tbl_districts_districtid = '0'
AND residence = '0'
AND aspect = '2' ) AS difference
FROM tbl_populations
WHERE fk_tbl_states_stateid = '16'
AND fk_tbl_districts_districtid = '0'
AND residence = '0'
AND aspect = '1'

我收到Subquery returns more than 1 row错误。

我如何获得所有结果？

Answer 1

SELECT Table11.fk_tbl_states_stateid,Table1.Gender,Table1.value - table2.Value as Diff
From
(SELECT *
FROM tbl_populations
WHERE fk_tbl_states_stateid = '16'
AND fk_tbl_districts_districtid = '0'
AND residence = '0'
AND aspect = '2' ) Table1,
(SELECT value,Gender
FROM tbl_populations
WHERE fk_tbl_states_stateid = '16'
AND fk_tbl_districts_districtid = '0'
AND residence = '0'
AND aspect = '1' ) Table2
Where Table1.Gender = Table2.Gender

Answer 2

为它使用一个函数，应该很容易

查找子查询中的差异结果会在mysql错误中返回多于1行

2 个答案: