SQL DELETE Vs DROP Statement
The commands DELETE and DROP are used to remove database elements.
DROP is a Data Definition Language command.
whereas DELETE is a Data Manipulation Language command.
The difference between DELETE and DROP is that DELETE removes tuples from a table while DROP removes the entire table from the database.
SQL DELETE Statement
The DELETE statement in SQL is a Data Manipulation Language command. It's used to get rid of existing records from a table.
Depending on the condition supplied in the query, we can delete a single or several records.
The WHERE clause of the DELETE statement specifies the requirements.
If theWHERE clause is omitted from the DELETE statement, all tuples in the relation are destroyed by default, even if the relation containing those tuples still exists in the schema.
The DELETE command cannot be used to delete a complete relation.
Example: This query deletes the record(s) from the Persons table with the value 3 in the field MemberID .
| MemberID | FName | Lname | City |
|---|---|---|---|
| 303 | Raghul | M | Chenni |
| 305 | Vishal | R | Bangalore |
| 345 | Mani | V | Hydrabad |
To write above table in query,
DELETE FROM Persons WHERE MemberID=305; Output: The Output of above query is
| MemberID | FName | Lname | City |
|---|---|---|---|
| 303 | Raghul | M | Chenni |
| 345 | Mani | v | Bangalore |
SQL DROP Statement
The DROP statement is a Data Definition Language (DDL) command for deleting existing database items.
It allows you to delete databases, tables, views, and triggers, among other things. In SQL, a DROP command deactivates a component in a relational database management system (RDBMS).
You can even use the DROP command to remove an entire schema.
CASCADE and RESTRICT are two behavioural options for the DROP command.
When CASCADE is used to DROP the schema, it removes any relevant pieces such as the schema's relations, domains, and constraints.
When you use CASCADE to remove a relation (table) from a schema, it also removes all the constraints, views, and elements that refer to the relation being discarded.
Example: This query deletes the whole Company table from the database.
| MemberID | FName | Lname | City |
|---|---|---|---|
| 303 | Raghul | M | Chenni |
| 305 | Vishal | R | Bangalore |
| 345 | Mani | V | Hydrabad |
To write above table in query,
DROP TABLE Persons; Output: The output of above query is
SQL Difference Between DELETE And DROP Statement
There are 15 main contrasts in delete vs drop :-
| DELETE | DROP |
|---|---|
| DELETE deletes one or more tuples from a table. | DROP can be used to delete a entire table, domain, or constraints. |
If we want to delete all the records in a table, we should use TRUNCATE rather than DELETE because the former is faster. |
With exception of TRUNCATE, which just deletes the table's data, the DROP command deletes the table's data as well as the table's whole schema/structure from the database. |
| DELETE is a Data Manipulation Language Command, which means it may be undone. | Because DROP is a DDL command, it cannot be reversed. |
| It's based on a data buffer. | It is a data-driven system. |
The DELETE command can be combined with the WHERE clause. |
With the DROP command, no clause is utilised. |
| If all records are erased with the Delete Command, the table memory space is not free. | The Drop command frees up memory. |
| The DELETE command may run out of memory. | Memory fragmentation may occur if you use the DROP command. |
| SQL communicates with the database server directly. | PL/SQL does not communicate directly with the database server. |
| SQL is a data-oriented programming language. | PL/SQL is an application-oriented programming language. |
| SQL is used to generate and execute DDL and DML statements, as well as compose queries. | PL/SQL is a programming language that may be used to create programme blocks, functions, procedures, triggers. |
| DELETE command, table view exists. | There is no view of table in the DROP operation. |
| Integrity limitations will not be removed using this command. | Integrity limitations will be eliminated using the DROP command. |
| Undo space is used in this command, but it is less than DELETE. | Undo space is not used in the DROP command. |
| The DELETE command is faster than the DROP command. | The DROP command is simple to use, but it has a few drawbacks. |
| Size is fixed. | It is possible to resize |