连接 5 个表，但不包括第 5 个表的值

Question

数据表

我有 5 个具有特定值的表：

1. 表：tbl_1

+-------+-------+
| nm_id | name  |
+-------+-------+
|     1 | name1 |
|     2 | name2 |
|     3 | name3 |
+-------+-------+

1. 表：tbl_2

+-------+-------+-------+
|post_id| nm_id | post  |
+-------+-------+-------+
|     1 |     1 | text1 |
|     2 |     1 | text2 |
|     3 |     2 | text3 |
+-------+-------+-------+

1. 表：tbl_3

+-------+-------+-------+-------+
|com_id |post_id| nm_id | com   |
+-------+-------+-------+-------+
|     1 |     1 |     1 | text1 |
|     2 |     2 |     1 | text2 |
|     3 |     2 |     2 | text3 |
+-------+-------+-------+-------+

4. 表：tbl_4

+-------+-------+-------+-------+-------+
|com2_id|com_id||post_id| nm_id | com2  |
+-------+-------+-------+-------+-------+
|     1 |     1 |     1 |     1 | text1 |
|     2 |     2 |     2 |     1 | text2 |
|     3 |     1 |     2 |     2 | text3 |
+-------+-------+-------+-------+-------+

5. 表：tbl_5

+-------+-------+-------+-------+-------+-------+
|rep_id |com2_id|com_id||post_id| nm_id | text  |
+-------+-------+-------+-------+-------+-------+
|     1 |  null |     1 |     1 |     1 | text1 |
|     2 |  null |  null |     1 |     1 | text2 |
+-------+-------+-------+-------+-------+-------+

我尝试了什么

我需要获取所有值，但我的想法是从结果中排除 tbl_5 中的值。到目前为止，我所做的是：

1. 选择tbl_2 然后在nm_id 上加入tbl_1 然后在post_id 上排除tbl_5 -> 1stVariable

SELECT tbl_2.*, name.tbl_1
FROM tbl_2
INNER JOIN tbl_2 ON tbl_1.nm_id = tbl_2.nm_id
LEFT JOIN tbl_5 ON tbl_2.post_id = tbl_5.post_id
WHERE tbl_2.post_id = *variable* AND tbl_5.rep_id IS NULL

1. 选择tbl_3 然后在com_id 上加入tbl_2 然后在nm_id 上加入tbl_1 在com_id 上排除tbl_5 -> 2ndVariable

SELECT tbl_3.*, name.tbl_1
FROM tbl_3
INNER JOIN tbl_3 ON tbl_1.nm_id = tbl_3.nm_id
LEFT JOIN tbl_5 ON tbl_3.com_id = tbl_5.com_id
WHERE tbl_3.com_id = *variable* AND tbl_5.rep_id IS NULL

1. 选择tbl_4 然后在nm_id 上加入tbl_1 在com2_id 上排除tbl_5 -> 3rdVariable

SELECT tbl_4.*, name.tbl_1
FROM tbl_4
INNER JOIN tbl_4 ON tbl_1.nm_id = tbl_4.nm_id
LEFT JOIN tbl_5 ON tbl_4.com2_id = tbl_5.com2_id
WHERE tbl_4.com2_id = *variable* AND tbl_5.rep_id IS NULL

我当前的输出是 JSON

{
  post:{...},
  com:{...},
  com2:{...}
}

需要的 JSON 输出

发生的情况是我的 .js 变得如此长且复杂，包含 3 个单独的数组。我试图在第一个变量中获取所有内容，但我不明白如何在数组中获取数组：

{
   post: {
     post_id: "post_id",
     name: "name",
     com: {
       com_id:"com_id",
       com:"com",
       name:"name",
       com2:{
         com2_id:"com2_id",
         com2:"com2",
         name:"name",
         }
      },
   }
}

我真的希望这是可以理解的。提前致谢。

Answer 1

我希望这样的查询：

select . . .    -- columns you want
from . . .      -- joins among the first four tables
where not exists (select 1
                  from table_5 t5
                  where . . .    -- conditions that match table 5 to the other tables
                 );

我可以推测你的条件是这样的：

where not exists (select 1
                  from table_5 t5
                  where t5.com_id = t4.com_id and
                        t5.post_id = t2.post_id and
                        t5.nm_id = t1.nm_id
                 )

但您的问题不清楚表格是如何匹配的。