SQL DELETE Function
Quick summary: The SQL DELETE statement removes rows from a table.
SQL DELETE Syntax
DELETE FROM table_name WHERE conditionSQL
SQL DELETE Basic examples
DELETE FROM users WHERE id = 5;SQL
Output:
1 row deletedDeletes a specific row.
SQL DELETE Real-world usage
DELETE FROM sessions WHERE expires_at < NOW();SQL
Output:
Expired sessions deletedCleans up old data.
SQL DELETE Edge cases
DELETE FROM users;SQL
Output:
All rows deletedDeletes the entire table content.
SQL DELETE Common mistakes
Using DELETE instead of soft delete
Data is permanently removed.
Incorrect
DELETE FROM users WHERE id = 5;Correct
UPDATE users SET deleted_at = NOW() WHERE id = 5;Prefer soft deletes when possible.
SQL DELETE Frequently Asked Questions
What does DELETE do in SQL?
Removes rows from a table.
Basic syntax of DELETE?
DELETE FROM table WHERE condition.
Use case?
Removing data.
Common mistake?
Omitting WHERE deletes all rows.
Handles multiple rows?
Yes.
Performance?
Depends on size and indexes.
Safe?
Use transactions.
Rollback possible?
Yes.
Alternative?
TRUNCATE (faster but unsafe).
Handles cascade?
Yes with constraints.
Used with JOIN?
Yes in some DBs.
Best practice?
Always use WHERE.