Monday, January 4, 2010

Creating Joins with the ON Clause

• The join condition for the natural join is basically an equijoin of all columns with the same name.
• To specify arbitrary conditions or specify columns to join, the ON clause is used.
• The join condition is separated from other search conditions.
• The ON clause makes code easy to understand.

The ON Condition

Use the ON clause to specify a join condition. This lets you specify join conditions separate from any search or filter conditions in the WHERE clause.