SQL Joins
Let start with what is called as a Cartesian Product.
• A Cartesian product is formed when:
– A join condition is omitted
– A join condition is invalid
– All rows in the first table are joined to all rows in the second table
• To avoid a Cartesian product, always include a valid join condition in a WHERE clause.
The query below results in a Cartesian product because there are no join conditions.