mysql - Codeigniter SELECT 将检查超过 MAX_JOIN_SIZE 行

Question

我开发了一个考勤管理系统，我想通过运行以下查询来生成报告，这将是大量的行，我在共享主机上并收到以下错误:

查询:

SELECT 
 `attendance`.*, `users`.`id` AS user_id, 
CONCAT_WS(" ", `user_profiles`.`fname`, `user_profiles`.`lname` ) AS name,
`user_department`.`did`, `user_department`.`dep_name` FROM (`attendance`) 
    LEFT JOIN `users` ON `users`.`username` = `attendance`.`emp_code` 
    LEFT JOIN  `user_profiles` ON `user_profiles`.`user_id` = `users`.`id` 
    LEFT JOIN `in_department` ON `in_department`.`user_id` = `user_profiles`.`user_id`
    LEFT JOIN `user_department` ON `in_department`.`dep_id` = `user_department`.`did` 
WHERE `banned` = '0' 
   AND `for_date` >= '2012-05-28' 
   AND `for_date` <= '2012-06-28' 
ORDER BY `emp_code` asc, `for_date` asc

错误:

SELECT 将检查超过 MAX_JOIN_SIZE 行；检查您的 WHERE 并使用 SET SQL_BIG_SELECTS=1 或 SET MAX_JOIN_SIZE=# 如果 SELECT 没问题

我如何使用 codeigniter 中的事件记录运行此查询SET SQL_BIG_SELECTS=1

请帮忙，我需要索引我的表吗

Answer 1

您可以简单地发出包含 SET 命令的查询:

$this->db->query('SET SQL_BIG_SELECTS=1');