3
In SQL there are several types of JOIN
, what is the difference between INNER JOIN
, LEFT JOIN
, CROSS JOIN
, RIGHT JOIN
and FULL JOIN
?
3
In SQL there are several types of JOIN
, what is the difference between INNER JOIN
, LEFT JOIN
, CROSS JOIN
, RIGHT JOIN
and FULL JOIN
?
4
Being minimalist, and considering that A is always the table on the left, and B on the right:
Inner Join
= only records linked in tables A and B
Left Join
= all records of A, only the linked records of B.
Right Join
= all records of B, only the linked records of A.
Cross Join
= all linked records of A and B, all lines of A and all lines of B, and replicas of lines of A and B with variations between records of the same tables.
Full Join
= Left Join and Right Join together. Lines that are not connected do not appear.
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You may help: http://answall.com/q/6441/6454
– stderr
It helped, but the explanation of
CROSS JOIN
.– Florida
I understand @Bacco it would be good to close by duplicate.
– Florida
@Florida took advantage and added the cross in mine too, so gets more complete ;) - any doubt leave comment there, I try to clarify if you can. I was stalling to put, because I had not imagined how to make the graph, but I think today I got a reasonable solution
– Bacco