Which of the following is also called an INNER JOIN?a.EQUI JOINb.cross joinc.SELF JOINd.Full outer JoinClear my choice

Breakdown the Problem

1. Identify the types of joins in SQL.
2. Determine which of the options listed corresponds to an INNER JOIN.

Relevant Concepts

• INNER JOIN (also known as EQUI JOIN): This join returns records that have matching values in both tables involved in the join.
• CROSS JOIN: It returns the Cartesian product of the two tables, meaning it combines all rows from the first table with all rows from the second.
• SELF JOIN: A self join is a regular join but the table is joined with itself.
• FULL OUTER JOIN: This returns all records when there is a match in either left or right table records.

Analysis and Detail

1. EQUI JOIN is often used interchangeably with INNER JOIN, as it specifically looks for equality in the join condition.
2. CROSS JOIN does not apply due to its computational difference.
3. SELF JOIN is specific to the same table and does not represent INNER JOIN.
4. FULL OUTER JOIN extends beyond the concept of INNER JOIN by including unmatched rows.

Verify and Summarize

From the above analysis, it is clear that the terms EQUI JOIN and INNER JOIN are synonymous. Thus, it is evident which option is correct.

Final Answer

The option that is also called an INNER JOIN is a. EQUI JOIN.