MySQL LEFT join multi-table join query

Specific operations

MySQL supports the join syntax for select and some update and delete cases, with specific grammatical details:
Table_references:
Table_reference [, Table_reference] ...
Table_reference:
Table_factor
| Join_table
Table_factor:
Tbl_name [[as] alias]
[{use| ignore| FORCE} INDEX (Key_list)]
| (table_references)
| {OJ table_reference left OUTER JOIN table_reference
On conditional_expr}
Join_table:
table_reference [INNER | CROSS] JOIN table_factor [join_condition]
| Table_reference Straight_join Table_factor
| Table_reference straight_join Table_factor on condition
| Table_reference left [OUTER] JOIN table_reference join_condition
| Table_reference NATURAL [Left [OUTER]] JOIN table_factor
| Table_reference right [OUTER] JOIN table_reference join_condition
| Table_reference NATURAL [Right [OUTER]] JOIN table_factor
Join_condition:
On conditional_expr | USING (column_list)

In addition to the commonly used two table joins, the SQL (MySQL) JOIN syntax supports multiple table joins. The basic syntax for multiple table joins is as follows:

... From table1 inner| Left| Right JOIN table2 on condition inner| Left| Right JOIN table3 on condition ...

Join multiple table joins enable you to get related data from multiple tables, and here are three raw data tables:

Article Article table:

Aid	title	content	UID	Tid
1	Article 1	Article 1 text content ...	1	1
2	Article 2	Article 2 text content ...	1	2
3	Article 3	Article 3 text content ...	2	1
5	Article 5	Article 5 text content ...	4	1

User table:

UID	username	Email
1	Admin	Admin@5idev.com
2	Xiao ming	Xiao@163.com
3	Jack	Jack@gmail.com

Type Article Types table:

Tid	TypeName
1	General articles
2	Elite Articles
3	Draft

code is as follows	copy code
SELECT * from T1 left JOIN (T2, T3, T4) on (t2.a=t1.a and t3.b=t1.b and t4.c=t1.c)