SQLite更新查询-具有别名的子查询不起作用 [英] SQLite update query - subquery with aliases doesn't work

问题描述

我需要更新一个SQLite表。

I need to update a SQLite table.

表格如下：

ID   | Address            | CallNumber   |  RefID
-----+--------------------+-------------------------------------------
ef78 | library            | 2002/13      | 100002
no56 | Lit                | 0189         | 100003
rs90 | temp               |              | 100003

对于地址= Lit的每一列，都有地址='temp'的列相同的RefID。
现在，我需要使用相同的RefID从列中使用值 CallNumber更新每个Address = temp。

For every column with Address = "Lit" there is a column Address = 'temp' with the same RefID. Now I need to update each Address = "temp" with the value "CallNumber" from the column with the same RefID.

更新后的表应类似于：

ID   | Address            | CallNumber   |  RefID
-----+--------------------+-------------------------------------------
ef78 | library            | 2002/13      | 100002
no56 | Lit                | 0189         | 100003
rs90 | 0189               |              | 100003

我尝试了此操作：

UPDATE Location
SET address = foo.callnumber
FROM (select RefID, CallNumber FROM Location) foo
WHERE foo.RefID=Location.RefID AND Location.Address = 'temp';

但是我所得到的只是 from附近的语法错误。

But all I got is a syntax error near "from".

任何线索？

推荐答案

UPDATE 命令没有 FROM 子句。

使用相关子查询：

UPDATE Location
SET Address = (SELECT CallNumber
               FROM Location L2
               WHERE L2.RefID = Location.RefID
                 AND L2.Address = 'Lit')
WHERE Address = 'temp'

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