SQL | Distinct Clause

The distinct keyword is used in conjunction with select keyword. It is helpful when there is a need of avoiding duplicate values present in any specific columns/table. When we use distinct keyword only the unique values are fetched. 

Syntax : 

SELECT DISTINCT column1, column2 
FROM table_name 

column1, column2 : Names of the fields of the table.

table_name : Table from where we want to fetch the records.

This query will return all the unique combinations of rows in the table with fields column1, column2. 



NOTE: If distinct keyword is used with multiple columns, the distinct combination is displayed in the result set. 

Table – Student

ROLL_NO NAME ADDRESS PHONE AGE
1 RAM DELHI XXXXXXXXXX 18
2 RAMESH GURGAON XXXXXXXXXX 18
3 SUJIT ROHTAK XXXXXXXXXX 20
4 SURESH DELHI XXXXXXXXXX 18
3 SUJIT ROHTAK XXXXXXXXXX 20
2 RAMESH GURGAON XXXXXXXXXX 18

Queries

  • To fetch unique names from the NAME field –
     
SELECT DISTINCT NAME 
FROM Student;

Output : 

NAME
Ram
RAMESH
SUJIT
SURESH
  • To fetch a unique combination of rows from the whole table –
     
SELECT DISTINCT * 
FROM Student;

Output : 
 

ROLL_NO NAME ADDRESS PHONE Age
1 Ram Delhi XXXXXXXXXX 18
2 RAMESH GURGAON XXXXXXXXXX 18
3 SUJIT ROHTAK XXXXXXXXXX 20
4 SURESH Delhi XXXXXXXXXX 18

Note : Without the keyword distinct in both the above examples 6 records would have been fetched instead of 4, since in the original table there are 6 records with the duplicate values.

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