Using join, which of the following MySQL query is almost equivalent to:
SELECT NAME, MARKS FROM STUDENT, RESULT WHERE STUDENT.ROLL = RESULT.ROLL;

Correct option is A

The MySQL query that is almost equivalent to the given query SELECT NAME, MARKS FROM STUDENT, RESULT WHERE STUDENT.ROLL = RESULT.ROLL; is SELECT NAME, MARKS FROM STUDENT JOIN RESULT;. The default JOIN in MySQL is an INNER JOIN, which will return rows where the values of ROLL are the same in both the STUDENT and RESULT tables, just like the WHERE STUDENT.ROLL = RESULT.ROLL condition in the original query.
Important Key Points:
1. INNER JOIN: The JOIN keyword without any specific type defaults to an INNER JOIN, which retrieves records where there is a match between the tables based on the condition in the ON clause or the WHERE clause.
2. Combining Data: This query combines data from two tables, STUDENT and RESULT, where the ROLL values match in both tables.
3. Implicit Join: The given query uses an implicit join via the WHERE clause, which is equivalent to the explicit INNER JOIN syntax.
4. Default Behavior: The JOIN keyword, without any additional modifiers like LEFT or RIGHT, behaves as an INNER JOIN by default.
Knowledge Booster:
· Option (b): EQUI JOIN is not a valid syntax in MySQL. Typically, EQUI JOIN refers to a condition where tables are joined based on equality (e.g., ON STUDENT.ROLL = RESULT.ROLL), but the term itself is not used as an actual keyword in MySQL.
· Option (c): The NATURAL JOIN automatically joins tables based on columns with the same name in both tables. In this case, it would attempt to join on all columns with the same name, which may not be the intended behavior, as the original query specifically joins on the ROLL column. Hence, this is not equivalent.
· Option (d): This option is the same as the original query, which implicitly joins STUDENT and RESULT using a Cartesian product (cross join). However, it does not enforce the condition STUDENT.ROLL = RESULT.ROLL. This would result in a much larger result set and is not the same as an inner join.