SELECT t1.id, t2.DOCSUBJECT, max(t3.imagefileid) AS imagefileid FROM uf_wdcdzsxbd t1 JOIN docdetail t2 ON t1.tm = t2.id JOIN docimagefile t3 ON t2.id = t3.docid WHERE t1.id IN (3, 2, 1) GROUP BY t1.id ORDER BY CASE t1.id WHEN 3 THEN 1 WHEN 2 THEN 2 WHEN 1 THEN 3 END;这句sql会报错,原因时group by中没有包含全部的查询字段,如何修改
时间: 2023-12-06 09:04:53 浏览: 110
【路径规划】乌燕鸥算法栅格地图机器人最短路径规划【含Matlab仿真 2886期】.zip
如果您的SQL查询语句报错,而错误的原因是因为`GROUP BY`中没有包含全部的查询字段,可以按照以下步骤进行修改:
1. 将查询字段`imagefileid`添加到`GROUP BY`子句中,以便让Oracle知道需要按照哪个字段进行分组:
```
SELECT t1.id, t2.DOCSUBJECT, max(t3.imagefileid) AS imagefileid
FROM uf_wdcdzsxbd t1
JOIN docdetail t2 ON t1.tm = t2.id
JOIN docimagefile t3 ON t2.id = t3.docid
WHERE t1.id IN (3, 2, 1)
GROUP BY t1.id, t2.DOCSUBJECT, t3.imagefileid
ORDER BY CASE t1.id
WHEN 3 THEN 1
WHEN 2 THEN 2
WHEN 1 THEN 3
END;
```
2. 如果您不希望将查询结果按照`imagefileid`进行分组,而只想按照`t1.id`进行分组,则可以使用Oracle中的聚合函数`LISTAGG`来将`imagefileid`的值按照逗号分隔符进行合并:
```
SELECT t1.id, t2.DOCSUBJECT, LISTAGG(t3.imagefileid, ',') WITHIN GROUP (ORDER BY t3.imagefileid DESC) AS imagefileid_list
FROM uf_wdcdzsxbd t1
JOIN docdetail t2 ON t1.tm = t2.id
JOIN docimagefile t3 ON t2.id = t3.docid
WHERE t1.id IN (3, 2, 1)
GROUP BY t1.id, t2.DOCSUBJECT
ORDER BY CASE t1.id
WHEN 3 THEN 1
WHEN 2 THEN 2
WHEN 1 THEN 3
END;
```
在这个查询中,我们使用`LISTAGG`函数将`imagefileid`的值按照逗号分隔符进行合并,并将结果命名为`imagefileid_list`。我们还使用`WITHIN GROUP`子句来指定按照`imagefileid`进行排序,并将排序结果合并到一个字符串中。最后,我们将`imagefileid_list`添加到`SELECT`子句中,以便让Oracle返回合并后的结果。
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