In PostgreSQL, AND and OR, also known as join operators, are used to narrow the scope of a query when querying data, and we can specify one or more query conditions with AND or OR. The AND operator indicates that one or more conditions must be true at the same time. In Create the COMPANY table ( 下载 COMPANY SQL 文件 ), the data are as follows: The following example reads that the AGE field is greater than 25 and The OR operator means that only any one of several conditions needs to be satisfied. In Create the COMPANY table ( 下载 COMPANY SQL 文件 ), the data are as follows: The following example reads 5.18.1. AND ¶
WHERE
In the clause, the syntax for using AND is as follows:SELECT column1, column2, columnN
FROM table_name
WHERE [condition1] AND [condition2]...AND [conditionN];
5.18.2. Example ¶
runoobdb# select * from COMPANY;
id | name | age | address | salary
----+-------+-----+-----------+--------
1 | Paul | 32 | California| 20000
2 | Allen | 25 | Texas | 15000
3 | Teddy | 23 | Norway | 20000
4 | Mark | 25 | Rich-Mond | 65000
5 | David | 27 | Texas | 85000
6 | Kim | 22 | South-Hall| 45000
7 | James | 24 | Houston | 10000
(7 rows)
SALARY
All records with fields greater than or equal to 65000:runoobdb=# SELECT * FROM COMPANY WHERE AGE >= 25 AND SALARY >= 65000;
id | name | age | address | salary
----+-------+-----+------------+--------
4 | Mark | 25 | Rich-Mond | 65000
5 | David | 27 | Texas | 85000
(2 rows)
5.18.3. OR ¶
WHERE
In the clause, the syntax for using OR is as follows:SELECT column1, column2, columnN
FROM table_name
WHERE [condition1] OR [condition2]...OR [conditionN]
runoobdb# select * from COMPANY;
id | name | age | address | salary
----+-------+-----+-----------+--------
1 | Paul | 32 | California| 20000
2 | Allen | 25 | Texas | 15000
3 | Teddy | 23 | Norway | 20000
4 | Mark | 25 | Rich-Mond | 65000
5 | David | 27 | Texas | 85000
6 | Kim | 22 | South-Hall| 45000
7 | James | 24 | Houston | 10000
(7 rows)
AGE
Field greater than or equal to 25 or
SALARY
All records with fields greater than or equal to 65000:runoobdb=# SELECT * FROM COMPANY WHERE AGE >= 25 OR SALARY >= 65000;
id | name | age | address | salary
----+-------+-----+------------+--------
1 | Paul | 32 | California | 20000
2 | Allen | 25 | Texas | 15000
4 | Mark | 25 | Rich-Mond | 65000
5 | David | 27 | Texas | 85000
(4 rows)