Sql 从数据库中选择错误

要求显示user1和user2，而不是显示user5和user1。 我使用

DBIC_TRACE=1

跟踪SQL生成的查询，结果是：

INSERT INTO user_access_rights ( access_rights_id, date_begin, date_end, username) 
    VALUES ( ?, ?, ?, ? ) 
    RETURNING id: 'level1', '2019-10-28T07:43:29', '2019-10-29T07:43:29', 'user1' 
INSERT INTO user_access_rights ( access_rights_id, date_begin, date_end, username) 
    VALUES ( ?, ?, ?, ? ) 
    RETURNING id: 'level1', '2019-10-28T07:43:29', '2019-10-29T07:43:29', 'user2' 
INSERT INTO user_access_rights ( access_rights_id, date_begin, date_end, username) 
    VALUES ( ?, ?, ?, ? ) 
    RETURNING id: 'level1', '2019-10-28T07:43:29', '2019-10-29T07:43:29', 'user3' 
INSERT INTO user_access_rights ( access_rights_id, date_begin, date_end, username) 
    VALUES ( ?, ?, ?, ? ) 
    RETURNING id: 'level1', '2019-10-28T07:43:29', '2019-10-29T07:43:29', 'user4' 
INSERT INTO user_access_rights ( access_rights_id, date_begin, date_end, username) 
    VALUES ( ?, ?, ?, ? ) 
    RETURNING id: 'level1', '2019-10-28T07:43:30', '2019-10-29T07:43:30', 'user5' 
INSERT INTO user_access_rights ( access_rights_id, date_begin, date_end, username) 
    VALUES ( ?, ?, ?, ? ) 
    RETURNING id: 'level2', '2019-10-28T07:43:30', '2019-10-29T07:43:30', 'user6' 
INSERT INTO user_access_rights ( access_rights_id, date_begin, date_end, username) 
    VALUES ( ?, ?, ?, ? ) 
    RETURNING id: 'level2', '2019-10-28T07:43:30', '2019-10-29T07:43:30', 'user7' 
INSERT INTO user_access_rights ( access_rights_id, date_begin, date_end, username) 
    VALUES ( ?, ?, ?, ? ) 
    RETURNING id: 'level2', '2019-10-28T07:43:30', '2019-10-29T07:43:30', 'user8' 
INSERT INTO user_access_rights ( access_rights_id, date_begin, date_end, username) 
    VALUES ( ?, ?, ?, ? ) 
    RETURNING id: 'level2', '2019-10-28T07:43:30', '2019-10-29T07:43:30', 'user9' 
INSERT INTO user_access_rights ( access_rights_id, date_begin, date_end, username) 
    VALUES ( ?, ?, ?, ? ) 
    RETURNING id: 'level2', '2019-10-28T07:43:30', '2019-10-29T07:43:30', 'user10' 
INSERT INTO user_access_rights ( access_rights_id, date_begin, date_end, username) 
    VALUES ( ?, ?, ?, ? ) 
    RETURNING id: 'level2', '2019-10-28T07:43:30', '2019-10-29T07:43:30', 'user11'

SELECT COUNT( * ) 
FROM user_access_rights me 
WHERE ( ( access_rights_id = ? AND date_end >= ? ) ): 'level1', '2019-10-28 07:43:30+0000' 

SELECT access_rights_recipient.username, access_rights_recipient.last_login, me.access_rights_id 
FROM user_access_rights me 
JOIN users access_rights_recipient ON access_rights_recipient.username = me.username 
WHERE ( ( access_rights_id = ? AND date_end >= ? ) ) 
ORDER BY date_begin DESC, username ASC LIMIT ?: 'level1', '2019-10-28 07:43:30+0000', '2'

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有人能解释一下为什么会发生这种情况吗？级别为

1

和

user2

的记录的

date\u end

值为

2019-10-29T07:43:29

，在查询中的限制之前。

具有

level1

和

user2

的记录的

date\u end

值是

2019-10-29T07:43:29

，就在查询中的限制之前。

谢谢您的回答！但是我注意到查询中的日期结束值是2019-10-28 07:43:30+0000。您能告诉我更多细节吗？因为这是一个不可靠的答案，有时我得到了正确的答案，有时我得不到。例如：我再次运行并显示user4和user5。谢谢！谢谢你的回答！但是我注意到查询中的日期结束值是2019-10-28 07:43:30+0000。您能告诉我更多细节吗？因为这是一个不可靠的答案，有时我得到了正确的答案，有时我得不到。例如：我再次运行并显示user4和user5。谢谢！