Using the SQL INNER JOIN keyword Tutorial

Using the SQL INNER JOIN keyword Tutorial

INNER JOIN keyword When returning rows at least one race in the table.

SQL syntax for INNER JOIN

SELECT column_name (s) from
table_name1
INNER JOIN table_name2 on 
table_name1.column_name=table_ Name2.column_name

PS: The INNER join is the same as JOIN.
Okay, let's take a look at an example.

  
   Address 
      City 
    

 
   
   
 
    
 
     
p_id
 
     
LastName
 
     
FirstName
 
     
 
    
 
     
1
 
     
Hansen
 
     
Ola
 
     
TIMOTEIVN 10
 
     
Sandnes
 
    
 
    
 
     
2
 
     
Svendson
 
     
Tove
 
     
BORGVN 23
 
     
Sandnes
 
    
 
    
 
     
3
 
     
Pettersen
 
     
Kari
 
     
STORGT 20
 
     
Stavanger
 
    
 
   

  
  
Let's look at the Orders table.

  
  

 
   
   
 
    
 
     
_id
 
     
OrderNo
 
     
p_id
 
    
 
    
 
     
1
 
     
77895
 
     
3
 
    
 
    
 
     
2
 
     
44678
 
     
3
 
    
 
    
 
     
3
 
     
22456
 
     
1
 
    
 
    
 
     
4
 
     
24562
 
     
1
 
    
 
    
 
     
5
 
     
34764
 
     
15
 
    
 
   

  
  

  
  

   
   

   
Now, we're going to list all the people in any order.

We use the following SELECT statement:
   

   
   

   

   

   
   
SELECT Persons.lastname, Persons.firstname, Orders.orderno from
Persons
INNER JOIN Orders on
persons.p_id =orders.p_id ORDER BY
Persons.lastname

   
   


   
   
 
     
     

  
      
      
 
       
 
        
LastName
 
        
FirstName
 
        
OrderNo
 
       
 
       
 
        
Hansen
 
        
Ola
 
        
22456
 
       
 
       
 
        
Hansen
 
        
Ola
 
        
24562
 
       
 
       
 
        
Pettersen
 
        
Kari
 
        
77895
 
       
 
       
 
        
Pettersen
 
        
Kari
 
        
44678
 
       
 
      
 
     
     

   
   


   
   
 
     
     

  
      
      
Inner JOIN orders When the keyword returns a row at least one race in the table. If there are any "orders" that are listed in "people" that do not match,
  
      
      
These lines will not be listed.
  
      
      
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