Statement collection for SQL multiple table queries

Today we're going to talk about the SQL statements about how to query multiple tables, first and foremost, the most common and sudden, and the most abrupt. Multi-Table Query method

SELECT * FROM A join B in A.uid=b.uid join C on C.uid=a.uid where uid=1

二、四个 Table Query

SELECT * Form a,b,c,d where A.uid=b.uid and B.uid=c.uid and C.uid=d.uid where uid=1

Third, the use of alias query

SELECT * FROM table1 as a,table2 as B where a.id=b.id and a.id=2

Four, left JOIN table query

SELECT * FROM table1 a LEFT join Table2 b where a.id=b.id and a.id=2

The above four query statements, the most speed to calculate left join, and finally if not in the must not have to use a multiple table joint query Oh.