Sqlite:'in'子句中可以有多少个参数 [英] Sqlite : How many parameters can there be in an 'in' clause
问题描述
我想执行以下操作:
delete from images where image_address not in (<a long list>)
此列表可以多长时间? (我猜我可能要考虑另一种方式)。
How long can this list be? (I'm guessing I might have to think of another way).
推荐答案
如果您使用参数(?
),默认最大数量为999 。
If you are using parameters (?
), the maximum number is 999 by default.
如果通过直接插入值来动态创建SQL语句(这对字符串来说是一件坏事),这样的列表的长度没有上限。但是,限制整个SQL语句的长度,即100万默认情况下为字节。
If you are creating the SQL statement dynamically by inserting the values directly (which is a bad thing to do for strings), there is no upper limit on the lenght of such a list. However, there is a limit on the length of the entire SQL statement, which is one million bytes by default.
如果您不能保证查询不超过这些限制,则必须使用临时表(请参阅LS_dev的答案)。
If you cannot guarantee that your query does not exceed these limits, you must use a temporary table (see LS_dev's answer).
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