MySQL的：左连接和内部连接在一个子查询

Question

我有，我已经离开加盟，但我想从表3是内与表连接添加一个字段3个表2.

Table1 
id 
name 
surname 
table2_fk 

Table2 
id 
entry_name 
entry_code 
table3_fk 

Table3 
id 
type_name 
type_desc 

SELECT `Name`, `Type Description` 
(SELECT 
Table1.name AS `Name`, 
Table1.surname AS `Surname`, 
t2.entry_name AS `Entry`, 
t2.entry_code AS `Entry Code`, 
t3.type_name AS `Type Name`, 
t3.type_desc AS `Type Description` 

FROM Table1 
LEFT JOIN table2 AS t2 ON Table1.table2_fk = t2.id 
LEFT JOIN table3 AS t3 ON Table2.table3_fk = t3.id 
) as subquery 

我所需结果是有T2内连接T3，并从表1和表让现场3

根据我的子查询我想Name和Type Description显示

Answer 1

如果你想INNER JOIN表table2和table3然后LEFT JOIN到table1然后做到这一点：

SELECT t1.name, t.type_desc AS `Type Description` 
FROM Table1 AS t1 
LEFT JOIN (
    SELECT t2.id, t3.type_desc 
    FROM table2 AS t2 
    INNER JOIN table3 AS t3 ON t2.table3_fk = t3.id 
) AS t ON t1.table2_fk = t2.id 

但是，这可能是也许表示只是为：

SELECT t1.name, t3.type_desc AS `Type Description` 
FROM Table1 AS t1 
LEFT JOIN table2 AS t2 ON t1.table2_fk = t2.id 
LEFT JOIN table3 AS t3 ON t2.table3_fk = t3.id 

Answer 2

我相信你正在尝试左连接表1与内连接的结果表2和表3之间

select t1.name, t_res.type_desc from table1 t_1 
left join (
    select t_2.id, t_3.type_desc from table2 t_2 
    inner join table3 t_3 on t_2.table3_fk = t_3.id 
) as t_res on t_1.table2_fk = t_2.id