LEFT JOIN

Description

The LEFT JOIN keyword returns all records from the left table (table1), and the matching records from the right table (table2). The result is 0 records from the right side, if there is no match.

note

In some databases LEFT JOIN is called LEFT OUTER JOIN.

Syntax

> SELECT column_name(s)
FROM table1
LEFT JOIN table2
ON table1.column_name=table2.column_name;

Examples

```sql drop table if exists t1; drop table if exists t2; drop table if exists t3; create table t1 (libname1 varchar(21) not null primary key, city varchar(20)); create table t2 (isbn2 varchar(21) not null primary key, author varchar(20), title varchar(60)); create table t3 (isbn3 varchar(21) not null, libname3 varchar(21) not null, quantity int); insert into t2 values ('001','Daffy','Aducklife'); insert into t2 values ('002','Bugs','Arabbitlife'); insert into t2 values ('003','Cowboy','Lifeontherange'); insert into t2 values ('000','Anonymous','Wannabuythisbook?'); insert into t2 values ('004','BestSeller','OneHeckuvabook'); insert into t2 values ('005','EveryoneBuys','Thisverybook'); insert into t2 values ('006','SanFran','Itisasanfranlifestyle'); insert into t2 values ('007','BerkAuthor','Cool.Berkley.the.book'); insert into t3 values ('000','NewYorkPublicLibra',1); insert into t3 values ('001','NewYorkPublicLibra',2); insert into t3 values ('002','NewYorkPublicLibra',3); insert into t3 values ('003','NewYorkPublicLibra',4); insert into t3 values ('004','NewYorkPublicLibra',5); insert into t3 values ('005','NewYorkPublicLibra',6); insert into t3 values ('006','SanFransiscoPublic',5); insert into t3 values ('007','BerkeleyPublic1',3); insert into t3 values ('007','BerkeleyPublic2',3); insert into t3 values ('001','NYC Lib',8); insert into t1 values ('NewYorkPublicLibra','NewYork'); insert into t1 values ('SanFransiscoPublic','SanFran'); insert into t1 values ('BerkeleyPublic1','Berkeley'); insert into t1 values ('BerkeleyPublic2','Berkeley'); insert into t1 values ('NYCLib','NewYork');