Left outer join : Left Join « Join « SQL / MySQL

Left outer join

     
mysql>
mysql>
mysql> CREATE   TABLE PENALTIES
    ->         (PAYMENTNO      INTEGER      NOT NULL,
    ->          EmployeeNO       INTEGER      NOT NULL,
    ->          PAYMENT_DATE   DATE         NOT NULL,
    ->          AMOUNT         DECIMAL(7,2) NOT NULL,
    ->          PRIMARY KEY    (PAYMENTNO)          );
Query OK, 0 rows affected (0.00 sec)

mysql>
mysql> INSERT INTO PENALTIES VALUES (1,  6, '1980-12-08',100);
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO PENALTIES VALUES (2, 44, '1981-05-05', 75);
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO PENALTIES VALUES (3, 27, '1983-09-10',100);
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO PENALTIES VALUES (4,104, '1984-12-08', 50);
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO PENALTIES VALUES (5, 44, '1980-12-08', 25);
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO PENALTIES VALUES (6,  8, '1980-12-08', 25);
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO PENALTIES VALUES (7, 44, '1982-12-30', 30);
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO PENALTIES VALUES (8, 27, '1984-11-12', 75);
Query OK, 1 row affected (0.00 sec)

mysql>
mysql>
mysql>
mysql> CREATE   TABLE TEAMS
    ->         (TEAMNO         INTEGER      NOT NULL,
    ->          EmployeeNO       INTEGER      NOT NULL,
    ->          DIVISION       CHAR(6)      NOT NULL,
    ->          PRIMARY KEY    (TEAMNO)             );
Query OK, 0 rows affected (0.00 sec)

mysql>
mysql>
mysql> INSERT INTO TEAMS VALUES (1,  6, 'first');
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO TEAMS VALUES (2, 27, 'second');
Query OK, 1 row affected (0.00 sec)

mysql>
mysql> SELECT   TEAMS.EmployeeNO, TEAMS.TEAMNO, PENALTIES.PAYMENTNO
    -> FROM     TEAMS LEFT OUTER JOIN PENALTIES
    ->          ON TEAMS.EmployeeNO = PENALTIES.EmployeeNO
    -> WHERE    DIVISION = 'second';
+------------+--------+-----------+
| EmployeeNO | TEAMNO | PAYMENTNO |
+------------+--------+-----------+
|         27 |      2 |         3 |
|         27 |      2 |         8 |
+------------+--------+-----------+
2 rows in set (0.00 sec)

mysql>
mysql>
mysql> SELECT   TEAMS.EmployeeNO, TEAMS.TEAMNO, PENALTIES.PAYMENTNO
    -> FROM     TEAMS LEFT OUTER JOIN PENALTIES
    ->          ON TEAMS.EmployeeNO = PENALTIES.EmployeeNO
    ->          AND DIVISION = 'second';
+------------+--------+-----------+
| EmployeeNO | TEAMNO | PAYMENTNO |
+------------+--------+-----------+
|          6 |      1 |      NULL |
|         27 |      2 |         3 |
|         27 |      2 |         8 |
+------------+--------+-----------+
3 rows in set (0.00 sec)

mysql>
mysql> drop table teams;
Query OK, 0 rows affected (0.00 sec)

mysql> drop table PENALTIES;
Query OK, 0 rows affected (0.00 sec)

Related examples in the same category

1.	LEFT JOIN tables
2.	'USING' command in LEFT JOIN
3.	Two LEFT JOIN in select command
4.	Two LEFT JOIN
5.	Creating the table list with LEFT JOIN and then forming the linking connection with ON
6.	A LEFT JOIN and a regular join
7.	To list each author record, whether or not there are any book records for it, use a LEFT JOIN
8.	To force each category to be displayed, use a reference table and a LEFT JOIN.
9.	Creating Left Joins
10.	Replacing the ON clause with the USING clause for Left Join
11.	Use a left join to link more than two tables.
12.	Addition of the LEFT keyword to each join definition
13.	Left Joins (Left Outer Joins)
14.	Performing a LEFT JOIN on just the customer and sales tables.
15.	Table order in a LEFT JOIN is important.
16.	Left outer join syntax
17.	Left outer join then order
18.	Left outer join with using clause
19.	Left outer join with subquery
20.	Query from left outer join
21.	To return all the sales reps who have not yet made a sale