DELETE statement¶
The DELETE statement removes one or more rows from a table based on specified conditions. It allows developers to selectively delete data from a table, providing a way to manage and maintain the database by removing unnecessary or outdated records.
Advantages and Disadvantages of Using DELETE Statement¶
Trade-offs | Description |
---|---|
Advantages | Allows selective removal of specific rows from a table, helping to maintain data integrity and manage database resources efficiently. |
Can be combined with WHERE clause to delete rows that meet certain conditions, providing flexibility in data manipulation. | |
Provides a straightforward way to remove unwanted data without affecting the structure of the table or other related tables. | |
Disadvantages | Deleting large amounts of data can impact performance and may require careful consideration to avoid unintended consequences. |
Deletes are permanent and irreversible, so it’s crucial to double-check conditions and backup data before executing DELETE queries. |
Syntax of DELETE Statement¶
The statement has the following options:
Option | Description |
---|---|
DELETE FROM table_name |
This clause specifies the table from which you want to delete rows. |
WHERE condition (Optional) |
This clause filters the rows to be deleted based on a specific condition. If omitted, all rows in the table will be deleted. |
The syntax of the DELETE statement is as follows:
DELETE FROM table_name
[WHERE condition];
Example of DELETE Statement¶
This example deletes all rows from the orders
table where the order_date
is before January 1, 2023.
DELETE FROM orders
WHERE order_date < '2023-01-01';
Fundamental SQL links:
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Last update:
2024-06-21