Question

我试图将这两个SQL查询结合起来。

SELECT * FROM `history` WHERE `ID` = 56

SELECT * FROM `live` WHERE `ID` = 56 AND `ACTIVE` = 0 AND t1.`Shown` = 'complete'

我尝试过这样的事情：

SELECT t1.*,t2.*
FROM `history` t1
JOIN `live` t2
ON t1.`ID` = 56 AND t1.`ACTIVE` = 0 AND t1.`Shown` = 'complete'
WHERE t2.`ID` = 56

但上述查询会导致从live中选择所有内容并忘记history。

预期结果：我希望从history和live中选择所有列ID is equal to 56。但有些情况会导致ID's中的history不存在live - 在这种情况下，我想从history中选择所有ID ID 1}}是平等的。

两个表都有不同的列。他们唯一的共同点是Using UNION with specific columns from both tables.。

解决方案：

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Answer 1

快速回答是：

SELECT t1.*,t2.*
FROM `live` t1
JOIN `history` t2
ON t1.id = t2.id
WHERE t2.`ID` = 56 AND t1.`ACTIVE` = 0 AND t1.`Shown` = 'complete'

但我想你应该用更多细节描述你的问题......

Answer 2

假设两个表都有相同的列，听起来好像你想在这里使用UNION。

SELECT Col1, Col2, ..., ColN
    FROM history 
    WHERE ID = 56
UNION
SELECT Col1, Col2, ..., ColN
    FROM live
    WHERE ID = 56 
        AND ACTIVE = 0 
        AND Shown = 'complete'

Answer 3

如果history和live表具有相同的数字（并且最好是类型）列，那么UNION查询可能就是您想要的：

SELECT * FROM `history` WHERE `ID` = 56
UNION ALL
SELECT * FROM `live` WHERE `ID` = 56 AND `ACTIVE` = 0 AND t1.`Shown` = 'complete'

如果列数不相同，则可以从两个表中选择相同数量的列以使查询起作用。

Answer 4

如果history和live具有相同数量（并且最好是类型）列，那么这可以帮助您

SELECT * FROM 
(
SELECT * FROM `history` WHERE `ID` = 56
UNION ALL
SELECT * FROM `live` WHERE `ID` = 56 AND `ACTIVE` = 0 AND t1.`Shown` = 'complete'
) as result

或

SELECT * FROM history h JOIN live l ON h.id = l.id WHERE h.id = 56 AND l.id= 56 AND l.`ACTIVE` = 0 AND l.`Shown` = 'complete'

将两个SQL查询与不同的where和返回的唯一行组合在一起

4 个答案: