Microsoft® SQL Server® 2012 Bible

230

Part II: Building Databases and Working with Data

FIGURE 9-7

A graphical representation of a cross join is simply two tables without a join condition.

The result of a join without restriction is that every row in table Customer2 matches with

every row from table SalesOrder2:

CustomerID LastName OrderNumber

----------- ------------------ ---------------

101 Smith 1

102 Adams 1

103 Reagan 1

101 Smith 2

102 Adams 2

103 Reagan 2

101 Smith 3

102 Adams 3

103 Reagan 3

Exotic Joins

Nearly all joins are based on a condition of equality between the primary key of a primary

table and the foreign key of a secondary table, which is why the inner join is sometimes

called an equi-join. Although it’s commonplace to base a join on a single equal condition, it

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