YouTip

# PostgreSQL DISTINCT Keyword In PostgreSQL, the DISTINCT keyword is used with the SELECT statement to remove duplicate records and retrieve only unique records. When operating on data, it is possible to have multiple duplicate records in a table. When extracting such records, the DISTINCT keyword becomes particularly useful as it retrieves only unique records instead of duplicate ones. ### Syntax The basic syntax of the DISTINCT keyword used to remove duplicate records is as follows: ```sql SELECT DISTINCT column1, column2,.....columnN FROM table_name WHERE ### Examples Create a COMPANY table ((https://static.jyshare.com/download/company.sql)), with the following data: ```sql tutorialdb# 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) Let us insert two more rows: ```sql INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (8, 'Paul', 24, 'Houston', 20000.00); INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (9, 'James', 44, 'Norway', 5000.00); Now let us check the data in the table: ```sql tutorialdb# 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 8 | Paul | 24 | Houston | 20000 9 | James | 44 | Norway | 5000 (9 rows) Now let us use the DISTINCT keyword to get unique records: ```sql tutorialdb# SELECT DISTINCT name FROM COMPANY; The above PostgreSQL statement will produce the following result: ```sql name ------- Teddy Paul Mark James Allen David Kim (7 rows) You can see that the duplicate name "Paul" and "James" have been removed and only unique names are displayed.