Difference Between Equal and IN operator in SQL

The equal and IN operators are commonly used comparison operators in SQL. While they serve similar purposes in filtering data, there are key differences in their functionality and use cases. Understanding when to use each operator can help optimize our queries and make them more readable.

In this article, we will explain the differences between the = operator and the IN operator in SQL, with examples and best practices.

Key Differences Between Equal and IN Operators

What is the Equal Operator in SQL?

The = operator is used to compare a column value to a specific value. It is the most basic comparison operator and is useful when we need to check if a value in a column matches exactly with a single specified value. Consider a Student table with the following columns:

To fetch students whose address is either 'Delhi' or 'Rohtak', you would use the = operator with an OR condition:

Query:

SELECT * 
FROM Student 
WHERE ADDRESS='Delhi' OR ADDRESS='ROHTAK'; 

Output

IN Operator

The IN operator is used to compare a column value against a set of values. This operator allows us to specify multiple values in a single query, which is particularly useful when you need to check if a column’s value is within a given list of options.

To fetch record of students with address as Delhi or ROHTAK. The SQL query using IN operator would be,

Query:

SELECT * 
FROM Student 
WHERE ADDRESS IN ('Delhi', 'ROHTAK'); 

Output

Conclusion

Both the Equal and IN operators are used for comparison in SQL, but they serve different purposes. The = operator is used when comparing a single value to a column, whereas the IN operator is more efficient and readable when comparing a column to multiple values. For queries with multiple conditions, using IN simplifies the syntax and improves code readability. Understanding when to use each operator will help us write more efficient, readable, and optimized SQL queries.