删除数据库的前X行 [英] Delete first X lines of a database

问题描述

是否有SQL命令删除数据库表的前X行?

is there an SQL command to delete the first X lines of a database table?

我有一个数据库表，其中包含一些信息，但没有id或自动递增值，还有一个程序处理该表的前X行. 之后，需要删除这些X行.所以标准查询是:

I have a database table containing some information but no id or auto-incrementing value and a program that processes the first X lines of this table. Afterwards these X lines need to be deleted. So the standard query is:

DELETE FROM table WHERE something = value;

因此，有没有一种方法可以构建像这样的查询:

So, is there a way to build a query like:

DELETE FROM table WHERE rownumber <= X;

我已经尝试过此命令，但是数据库没有任何反应. 你有什么线索吗?

I have tried this command, but nothing happens to the database.. Do you have any clue?

推荐答案

在删除时使用LIMIT:

DELETE FROM table WHERE condition LIMIT 10

或者，如果您不希望出现这种情况

Or, if you don't want the condition

DELETE FROM table LIMIT 10

请记住，删除行的顺序是不确定的-这取决于您的DBMS配置和表索引.您应包括ORDER BY，以便按定义的顺序删除文件，例如ORDER BY id ASC首先删除最低的ID.

Remember that the order in which rows will be deleted is undefined - it depends on your DBMS configuration and table indices. You should include an ORDER BY so that the deletion is done in a defined order, e.g. ORDER BY id ASC to delete the lowest IDs first.

有关更多详细信息，请参见有关DELETE的MySQL文档.

See the MySQL documentation for DELETE for more details.

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