Tuesday, February 1, 2011

CROSS JOINS

    Cross joins produce all possible combinations of rows from tables which are joining. If we have again table A and table B, and each table has 3 rows, cross joins will produce 3x3=9 rows.

    Examples:

    clip_image001

Pure natural join can produce also an cartesian product when the joining tables do not have identical named columns.

Example :

image

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