SQL Joins | Dataford Interview Questions

What are the different types of SQL joins?

Asked in the Screening Round stage. This was an opening SQL fundamentals question in the 15-minute screening call.

Using the supplied employees and departments tables, write a query that demonstrates common join types by returning the number of rows produced by each one.

Output

One row per join type, with columns join_type and row_count.
Include INNER, LEFT, RIGHT, FULL OUTER, and CROSS joins.
Order alphabetically by join_type.

Schema

employees

Column	Type	Description
employee_idPK	INT	Unique employee identifier
employee_name	VARCHAR(100)	Employee name
department_id	INT	Employee department identifier

departments

Column	Type	Description
department_idPK	INT	Unique department identifier
department_name	VARCHAR(100)	Department name

Your question is SQL Joins. Start with the requirements and the two tables in the Question tab.

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Problem