LIMIT 中的 MySQL 数学和 COUNT(*)

Question

是否可以让 MySQL LIMIT 有一个总行数除以 2 的偏移量，以便查询看起来像这样:

SELECT * FROM test LIMIT COUNT(*) / 2, 5

5 只是一个数字。

Answer 1

这是不可能的。

来自documentation :

Expressions can be used at several points in SQL statements, such as in the ORDER BY or HAVING clauses of SELECT statements, in the WHERE clause of a SELECT, DELETE, or UPDATE statement, or in SET statements.

同样来自 SELECT documentation :

The LIMIT clause can be used to constrain the number of rows returned by the SELECT statement. LIMIT takes one or two numeric arguments, which must both be nonnegative integer constants (except when using prepared statements).

您将不得不执行两个查询——一个用于计数，另一个用于限制。