|
|
Sql
Jointure Sql : Inner join et Left outer join |
Un bon exemple sur les jointures vaut mieux qu’un long discours : Voici 2 tables : Table_A | Table_B
| CA1 | CA2 | 1 | AA | 1 | AB | 2 | AC | 3 | AD | 5 | AF |
| CB1 | CB2 | 1 | BA | 2 | BB | 2 | BC | 3 | BD | 4 | BE |
| Voici le résultat de 3 requêtes sur ces 2 tables : Select * from Table_A Inner join Table_B on CA1=CB1 CA1 | CA2 | CB1 | CB1 | 1 | AA | 1 | BA | 1 | AB | 1 | BA | 2 | AC | 2 | BB | 2 | AC | 2 | BC | 3 | AD | 3 | BD | Select * from Table_A Left outer join Table_B on CA1=CB1 CA1 | CA2 | CB1 | CB1 | 1 | AA | 1 | BA | 1 | AB | 1 | BA | 2 | AC | 2 | BB | 2 | AC | 2 | BC | 3 | AD | 3 | BD | 5 | AF | NULL | NULL | Select * from Table_A Right outer join Table_B on CA1=CB1 CA1 | CA2 | CB1 | CB1 | 1 | AA | 1 | BA | 1 | AB | 1 | BA | 2 | AC | 2 | BB | 2 | AC | 2 | BC | 3 | AD | 3 | BD | NULL | NULL | 4 | BE | |
|
|
|
|
|
|