What does the “WHERE” clause do in SQL?

The “WHERE” clause in SQL is specifically designed to filter records from a database query based on specified conditions. When constructing a query, the WHERE clause allows the user to define criteria that must be met for records to be included in the results. This is essential for retrieving only the relevant data from potentially large datasets, enhancing efficiency and clarity.

For example, when querying a table for customers with a specific last name, the WHERE clause can be used to specify that only records where the last name matches the provided value should be returned. This filtering capability is crucial for data retrieval tasks, enabling targeted analysis and reporting.

Understanding the purpose of the WHERE clause is fundamental in SQL as it directly influences the output of SQL queries and allows for granular control over the data being handled.