Structured Query Language tutorial (delete command )

Delete command : 

The DELETE statement is used to delete rows in a table.

SQL DELETE Syntax

DELETE FROM table_name
WHERE some_column=some_value

Note: Notice the WHERE clause in the DELETE syntax. The WHERE clause specifies which record or records that should be deleted. If you omit the WHERE clause, all records will be deleted!

SQL DELETE Example

The "Persons" table:

P_Id LastName FirstName Address City
1 Hansen Ola Timoteivn 10  Sandnes
2 Svendson Tove       Borgvn 23 Sandnes
3 Pettersen Kari Storgt 20 Stavanger
4      Nilsen Johan Bakken 2       Stavanger
5      Tjessem Jakob Nissestien 67 Sandnes

Now we want to delete the person "Tjessem, Jakob" in the "Persons" table.

We use the following SQL statement:

DELETE FROM Persons
WHERE LastName='Tjessem' AND FirstName='Jakob'

The "Persons" table will now look like this:

P_Id   LastName  FirstName Address      City
1 Hansen Ola Timoteivn 10  Sandnes
2 Svendson Tove Borgvn 23 Sandnes
3 Pettersen Kari        Storgt 20 Stavanger
4 Nilsen Johan       Bakken 2 Stavanger

Delete All Rows

It is possible to delete all rows in a table without deleting the table. This means that the table structure, attributes, and indexes will be intact:

DELETE FROM table_name

or

DELETE * FROM table_name

Note: Be very careful when deleting records. You cannot undo this statement!