The command used to delete records is DELETE, and the syntax is: DELETE FROM table_name WHERE condition; condition specifies which records to delete. Use DELETE FROM table_name directly when deleting unconditionally, and use DELETE FROM table_name WHERE when deleting conditionally. condition, for example, DELETE FROM table_name WHERE age > 30 means to delete records with an age greater than 30 in the table.
The command used to delete records in SQL
In SQL, the command used to delete records isDELETE.
Syntax:
DELETE FROM table_name WHERE condition;
Where:
- table_name: The name of the table from which records are to be deleted.
- WHERE condition: Optional condition used to specify which records to delete. If this condition is omitted, all records in the table will be deleted.
Usage:
- Unconditional deletion:
To delete all records in the table , you can use the following syntax:
DELETE FROM table_name;
- Conditional deletion:
To delete records that meet specific conditions, you can use the following syntax:
DELETE FROM table_name WHERE condition;
For example, to delete all records in the table whose age is greater than 30, you can use the following syntax:
DELETE FROM table_name WHERE age > 30;
Note:
- DELETE command Irreversible, once executed, the selected records will be permanently deleted.
- Before using the DELETE command, always make sure you fully understand its impact.
- If you need to undo the deletion, you need to restore the data from backup.
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