The DELETE statement is used to delete records in a table.
The DELETE Statement
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!
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