Which join results in the intersection of two tables?

Which join results in the intersection of two tables?

• A. Outer Join
• B. Inner Join
• C. Natural Join
• D. Full Join

Answer: (B)

An Inner Join is designed to produce a result set that only includes rows where there is a match in both tables involved in the join. This means that it retrieves records from both tables based on a specified condition that typically involves a common column. As a result, the outcome is the intersection of the two tables, containing only the rows that exist in both. For instance, if one table contains customer orders and another contains customer details, the Inner Join would return only those orders that have corresponding customer details, effectively filtering out any entries without a match. In contrast, an Outer Join includes records that may not have corresponding matches in both tables. A Natural Join also retrieves matching records based on common columns but may automatically include all columns without needing to specify a join condition explicitly. A Full Join includes all records from both tables, resulting in a broader dataset that captures all data, not just the intersection. Thus, the Inner Join is the most appropriate choice for focusing on the overlapping data between two tables.

An Inner Join is designed to produce a result set that only includes rows where there is a match in both tables involved in the join. This means that it retrieves records from both tables based on a specified condition that typically involves a common column. As a result, the outcome is the intersection of the two tables, containing only the rows that exist in both.

For instance, if one table contains customer orders and another contains customer details, the Inner Join would return only those orders that have corresponding customer details, effectively filtering out any entries without a match.

In contrast, an Outer Join includes records that may not have corresponding matches in both tables. A Natural Join also retrieves matching records based on common columns but may automatically include all columns without needing to specify a join condition explicitly. A Full Join includes all records from both tables, resulting in a broader dataset that captures all data, not just the intersection. Thus, the Inner Join is the most appropriate choice for focusing on the overlapping data between two tables.