SQL DELETE Table

SQL DELETE, a fundamental operation, removes data from a database. It’s integral to database management, selectively deleting records based on specific conditions. This SQL DELETE operation is important for database size management, data accuracy, and integrity. The SQL DELETE is a command of Data Manipulation Language (DML), so it does not delete or modify the table structure but it delete only the data contained within the table. Therefore, any constraints, indexes, or triggers defined in the table will still exist after you delete data from it.

SQL DELETE TABLE Statement

The SQL DELETE TABLE statement is used to delete the existing records from a table in a database. If you wish to delete only the specific number of rows from the table, you can use the WHERE clause with the DELETE statement. If you omit the WHERE clause, all rows in the table will be deleted. The SQL DELETE statement operates on a single table at a time.

Syntax

Following is the basic syntax for using the SQL DELETE command in SQL

DELETE FROM table_name;

DELETE TABLE with WHERE Clause

We can use the SQL DELETE statement to delete specific rows from a table based on a single condition using the WHERE clause.

Syntax

Following is the syntax for deleting specific rows based on single condition

DELETE FROM table_name
WHERE condition;

SQL DELETE Example

let’s say we have a table called employees and we want to delete a specific employee from that table. Here’s an example SQL DELETE statement

DELETE FROM employees
WHERE employee_id = 123;

In this example:

• DELETE FROM employees indicates that we want to delete data from the employees table.
• WHERE employee_id = 123 specifies the condition that identifies which rows to delete. In this case, it’s deleting the employee whose employee_id is 123.

Conclusion

The conclusion of using the DELETE TABLE statement is that it permanently removes all rows from a table, effectively wiping out all data contained within it. Unlike the DELETE statement, which removes specific rows based on a condition, DELETE TABLE deletes all rows in one go, leaving the table structure intact. However, using DELETE TABLE requires caution as it’s irreversible, resulting in permanent data loss. It’s commonly employed to clear all data from a table, like refreshing test data or resetting a database to its initial state.

Frequently asked questions