这来自 MySQL数据库知识库:

LIMIT子句可用于约束SELECT语句返回的行数. LIMIT接受一个或两个数字参数，这两个参数都必须是非负整数常量(使用预处理语句时除外).

为使查询正常工作，您需要将其编写为准备好的语句，然后执行该语句.

For your query to work, you will need to write it as a prepared statement, and then execute that.

SET @a = (SELECT group_limit FROM groups WHERE groupid = 7471);

PREPARE STMT FROM 'SELECT * FROM user LIMIT ?';
EXECUTE STMT USING @a;