PHP / MYSQL：左连接没有得到正确的父详细信息

Question

SELECT smirt.id as mid,
pc.packet_name as pname, 
pcs.packet_name as mainn, 
smirt.p_status as st , 
smirt.new_value as weight , 
smirt.packet_id, 
smirt.parent_packet_id 
FROM issue_receive_process AS smirt 
LEFT JOIN packet_creation AS pc ON  pc.id = smirt.packet_id
LEFT JOIN packet_creation AS pcs ON pcs.id = pc.parent_packet_id 
WHERE smirt.type = 53
AND smirt.main_kapan_id IN(1,2) 
ORDER BY smirt.packet_id

从上面的查询我得到以下细节：

但上面是错误

因为pname是我的子包 和mainn是我的MAIN PACKET

其实我需要（应该是）pname（NULL，0004）和mainn（0003,0002）如下（图片下面是编辑图片）：

as 0003，0002是主要数据包，0004是0002的子包... 0003没有任何子包......

可以帮助我，我错了。

由于

更新：PARENT TABLE IMAGE thats（issue_receive_process AS smirt）

每位用户：KISHORE以下查询：

SELECT smirt.id
,smirt.packet_id
,smirt.main_kapan_id
,pc.id
,pc.packet_name
,pc.parent_packet_id 
FROM issue_receive_process AS smirt 
LEFT JOIN packet_creation AS pc ON  pc.id = smirt.packet_id
WHERE pc.packet_name IN ('0002','0003','0004') 
ORDER BY smirt.packet_id

以下是结果：

第二个更新表： packet_creation下面的详细信息如下面的查询

SELECT *
FROM `packet_creation`
WHERE `id`
IN ( 5, 11, 9 )
LIMIT 0 , 30

Answer 1

我对你想要的东西感到非常困惑。

在运行测试数据时，您拥有的SQL将提供您描述为错误的数据。它正在获取记录和数据包，然后该数据包为父。如果数据包没有父节点，则返回NULL（并且应该）。

我唯一能想到的是，如果没有父记录，那么你希望将子包ID作为父包返回，并将子包返回为NULL。

如果是这样的话： -

SELECT smirt.id as mid,
        IF(pcs.packet_name IS NULL, NULL, pc.packet_name) as pname, 
        IF(pcs.packet_name IS NULL, pc.packet_name, pcs.packet_name) as mainn, 
        smirt.p_status as st , 
        smirt.new_value as weight , 
        smirt.packet_id, 
        smirt.parent_packet_id 
FROM issue_receive_process AS smirt 
LEFT JOIN packet_creation AS pc ON  pc.id = smirt.packet_id
LEFT JOIN packet_creation AS pcs ON pcs.id = pc.parent_packet_id 
WHERE smirt.type = 53
AND smirt.main_kapan_id IN(1,2) 
ORDER BY smirt.packet_id

以上每个查询结果如下：

HENCE最终输出我认为它来自3,4,2但应该是0003,0002,0004

编辑 - 将字段转换为字符以尝试强制前导零： -

SELECT smirt.id as mid,
        IF(pcs.packet_name IS NULL, NULL, CAST(pc.packet_name AS CHAR)) as pname, 
        IF(pcs.packet_name IS NULL, CAST(pc.packet_name AS CHAR), CAST(pcs.packet_name AS CHAR)) as mainn, 
        smirt.p_status as st , 
        smirt.new_value as weight , 
        smirt.packet_id, 
        smirt.parent_packet_id 
FROM issue_receive_process AS smirt 
LEFT JOIN packet_creation AS pc ON  pc.id = smirt.packet_id
LEFT JOIN packet_creation AS pcs ON pcs.id = pc.parent_packet_id 
WHERE smirt.type = 53
AND smirt.main_kapan_id IN(1,2) 
ORDER BY smirt.packet_id