SQL DELETE and TRUNCATE

DELETE FROM Customers
WHERE customer_id = 4;

DELETE Syntax

The syntax of the SQL DELETE command is:

DELETE FROM table_name
[WHERE condition];

Here,

• table_name is the name of the table from which rows are to be deleted
• condition specifies which rows should be deleted
• [] indicates that the WHERE clause is optional.

Delete a Single Row in a Table

We can delete a single row in a table using the DELETE command. For example,

DELETE FROM Customers
WHERE customer_id = 5;

Here, the SQL command will delete a row from the Customers table if its customer_id is 5.

Delete all Rows in a Table

The WHERE clause determines which rows to delete. However, we can delete all rows at once if we omit the WHERE clause. For example,

DELETE FROM Customers;

Here, the SQL command deletes all rows from the Customers table.

Note: Be careful when you use DELETE. Records may be lost permanently if the database is not backed up.

Truncate Table in SQL

The TRUNCATE TABLE clause is another way to delete all rows from a table at once. For example,

TRUNCATE TABLE Customers;

Here, the SQL command deletes all rows from the Customers table.

Note: This command is not supported by our SQL online editor as it is based on SQLite.

SQL DELETE vs. TRUNCATE