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Forum:
Visual FoxPro
Catégorie:
Autre
Titre:
Divers
Thread ID:
00140002
Message ID:
00140384
Vues:
28
>What is the difference between a left join, right join and an inner join in a quick summary?

A Left Join gives you all the records in the first table, plus all the data on the second table that can be included in the first.
The Right Join is the opposite.
The Inner Join outputs all the data that has an exact match in both tables.

Table A Table B
---+---+--- ---+---
1 A 1 1 Q
2 B 2 W
3 C 2 3 E
4 D 3 4 R
5 E 1

The results for the different types of Joins would be:

A LJ B A RJ B A IJ B
---+--- ---+--- ---+---
A Q A Q A Q
B E Q C W
C W C W D E
D E D E E Q
E Q R

Got it?

HTH.
Alexandre Nobre
Alpha Bytes Computer Corp.

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