Question

What is the purpose of an equality join/equijoin/inner join/simple join?

1) To combine rows from two or more tables based on a related column
2) To sort the rows of a table in ascending order
3) To filter the rows of a table based on a condition
4) To calculate the average value of a column in a table

Answer 1

The purpose of an equality join is to combine rows from two or more tables based on a related column.

Step-by-step explanation:

The purpose of an equality join/equijoin/inner join/simple join is to combine rows from two or more tables based on a related column. This allows you to retrieve data from multiple tables that have a common column or key. When you perform an inner join, only the rows with matching values in the related column will be returned.

For example, suppose you have two tables: 'Students' and 'Grades'. The 'Students' table has columns such as student ID and name, and the 'Grades' table has columns such as student ID and score. By performing an inner join on the student ID column, you can retrieve the names of the students who have scored certain grades.

It is important to note that an equality join/equijoin/inner join/simple join is not used for sorting rows in ascending order, filtering rows based on a condition, or calculating averages. These tasks are achieved using other SQL operations like 'ORDER BY', 'WHERE', and 'GROUP BY' respectively.

Therefore, the correct answer is 1) To combine rows from two or more tables based on a related column.