SQL Tutorial: SQL SELECT DISTINCT instance tutorial

SQL Tutorial: SQL SELECT DISTINCT instance tutorial

This chapter explains how to select discrete speech.


Select different declarations in SQL
In a table, some columns may contain duplicate values. This is not a problem, however, sometimes you want to list only different (different) values on the table.

Can be used to return only unique (different) values.

SQL SELECT DISTINCT syntax.

SELECT DISTINCT column_name(s)FROM table_name

Let's take a look at an instance with no repeated records in distinct.

 
 

  
  
 
   
 
    
_Id
 
    
LastName
 
    
FirstName
 
    
Address
 
    
City
 
   
 
   
 
    
1
 
    
Hansen
 
    
Ola
 
    
Timoteivn 10
 
    
Sandnes
 
   
 
   
 
    
2
 
    
Svendson
 
    
Tove
 
    
Borgvn 23
 
    
Sandnes
 
   
 
   
 
    
3
 
    
Pettersen
 
    
Kari
 
    
Storgt 20
 
    
Stavanger
 
   
 
  
 
 

Now, we only want to select different values from the column named "city" from the above table.

We use the following SELECT statement:
SELECT DISTINCT City FROM Persons
 
The result is as follows.
  
  

   
   
 
    
 
     
City
 
    
 
    
 
     
Sandnes
 
    
 
    
 
     
Stavanger