[Enhancement] Added the outer join (#8058)

* Added the outer join

* Update joins.md

* Update joins.md

* Refactor example tables in joins.md for clarity

Updated the example tables in the joins section to remove HTML entities and improve readability.

* Format fix

Author: dakshdeepHERE

content/sql/concepts/joins/joins.md

@@ -40,6 +40,40 @@ An `OUTER JOIN` will combine rows from different tables even if the join conditi
 - [`RIGHT JOIN`](https://www.codecademy.com/resources/docs/sql/commands/right-join), which combines matches with all rows from the right-side table.
 - [`FULL OUTER JOIN`](https://www.codecademy.com/resources/docs/sql/commands/full-outer-join), which combines matches with all rows from the left- and right-side tables.
 
+## CROSS JOIN
+
+A `CROSS JOIN` clause combines each row from one table with each row from another in the result set. This result is also known as a `Cartesian product`. The following query returns every combination of `shirt_color` and `pants_color`:
+
+```sql
+SELECT shirts.shirt_color,
+   pants.pants_color
+FROM shirts
+CROSS JOIN pants;
+```
+
+For example, here's the `shirts` table:
+
+| shirt_color |
+| ----------- |
+| white       |
+| grey        |
+
+And the `pants` table:
+
+| pants_color |
+| ----------- |
+| light       |
+| dark        |
+
+The result of the query would contain every combination of the two tables:
+
+| shirt_color | pants_color |
+| ----------- | ----------- |
+| white       | light       |
+| white       | dark        |
+| grey        | light       |
+| grey        | dark        |
+
 ## UNION
 
 The [`UNION`](https://www.codecademy.com/resources/docs/sql/commands/union) clause is used to combine results that appear from multiple [`SELECT`](https://www.codecademy.com/resources/docs/sql/commands/select) statements and filter duplicates.