The DELETE statement in SQL is essential for managing data within relational databases. Whether removing specific records based on conditions, clearing entire tables, or utilizing subqueries for targeted deletions, SQL provides powerful tools for maintaining database cleanliness and efficiency. These examples demonstrate various ways to use the DELETE statement effectively to meet specific data management needs while ensuring data integrity and consistency.

Explanation:

The DELETE statement in SQL is used to remove one or more records from a table based on specified conditions. It is commonly used to maintain data integrity by removing outdated or unnecessary records from the database.

Example 1: Deleting Records Based on a Condition

DELETE FROM customers
WHERE customer_id = 1001;

Description: In this example, the DELETE statement removes the customer record from the customers table where the customer_id is 1001. This is useful when you need to delete a specific record identified by its unique identifier.

Example 2: Deleting All Records from a Table

DELETE FROM logs;

Description: This DELETE statement deletes all records from the logs table. It does not specify a WHERE clause, so it removes all rows in the table. This approach is helpful when you need to clear all data from a table, such as resetting logs or cleaning up temporary data.

Example 3: Deleting Records Using Subquery

DELETE FROM products
WHERE product_id IN (
    SELECT product_id
    FROM discontinued_products
);

Description: In this example, the DELETE statement uses a subquery to specify which records to delete from the products table. It removes products that are listed in the discontinued_products table, based on matching product_id. Subqueries provide flexibility in defining deletion criteria based on related data.