Are you familiar with the difference between Drop and Delete?
Delete and Drop commands are SQL statements and are used to remove data from a SQL database. The DML command Delete deletes data from a database. The user can specify whether to delete all or some data in a particular table. The Delete statement only removes the records from the table.
However, the structure of the table remains the same. Drop is a DDL statement (Data Definition Language), and behaves differently than the Delete command. This is not a conditional statement and deletes all data in the table. It also removes table structure, as well as any references to the table from the database. We now know the details and differences between Delete and drop.
Use the Delete Command
The Where clause can be used to specify the required condition. All table data will be removed if the Where clause does not appear with the Delete statement. The table structure is not altered by the Delete command. The user doesn’t need to specify the table structure to reuse it again. As it is a DML operation, Delete does not automatically commit after its execution.
This can then be undone to reverse the last operation. If you want to permanently make changes, then the Commit command should be used. The Delete statement records each row deleted in the Transaction Log. This slows down the process. It also does not deallocate space after the execution.
The syntax of the Delete statement is shown below.
DELETE FROM <table_name>
DELETE FROM <table_name> WHERE <condition>
How to Use Drop Statement
The Drop statement permanently removes all table records, as well as the integrity constraints, indexes, and privileges for the relevant table. All the tables’ relationships are also removed, as is the information regarding the table. If the user wishes to reuse the same table, they will need to define its structure as well as all references. Drop is a DDL command. Once the Drop command has been executed, the Drop command cannot be undone.
The user must be careful when using this command. The Drop command cannot be used on system tables or tables with foreign key constraints. The Drop command is not limited to SQL tables. It can also be used for database views and column columns. All data in these objects will disappear forever with them.
The syntax of the Drop command is shown below.
DROP TABLE <table_name>
What’s the difference between Drop and Delete?
- The Delete/Drop commands are used to remove data from tables in a database.
- The Delete command performs conditional deletions, while the Drop command removes all records from the table.
- The Drop command, on the other hand, removes both the entire table data and its structure as well as all references to the table from the database.
- Delete is DML, while Drop is DDL. The Delete operation is reversible and not auto-committed. However, Drop is not reversible as it’s an auto-committed operation.
- Drop cannot be applied to tables that are referenced with foreign keys. Instead, the Delete option can be selected.
- The Drop command is more complex than the SQL Delete statement and should only be used with care.
The key difference between DELETE and DROP in SQL below is given
- DELETE is used to delete some or all of the rows from a table. The DROP commands are used for removing schemas, tables, domains, or constraints from a database.
- DELETE, on the other hand, is a Data Manipulation Language Command.
- The DELETE command can be combined with a WHERE clause, but DROP cannot.
- The DELETE command allows you to roll back your actions, whereas the DROP command does not.
- DELETE does not remove the table, so no memory is released. However, the DROP command deletes all of the data and releases the space.
Below is a comparison table between Drop and Delete.
|BASIS OF COMPARISON||DELETE||Drop|
|The Basics||DELETE Remove some or all tuples in a table.||DROP removes the schema, tables, domains, and constraints in the database.|
|The Language of the Speaker||DELETE commands are part of the Data Manipulation Language.||DROP (Data Definition Language) is a command.|
|Clause||The WHERE clause is compatible with DELETE.||No clauses are used with DROP.|
|Backward||You can roll back actions performed by DELETE.||DROP cannot be used to reverse any actions.|
|Space||The table will still occupy memory space even if all the rows are deleted using DELETE.||When you delete a table using DROP, the memory space is freed up.|
The article will close with a closing paragraph
DELETE is a Data Manipulation Language command, a DML command. It is used for deleting rows within a table. ELETE, a Data Manipulation Language (DML) command, is used to delete tuples/records in a table/relation. DROP, on the other hand, is a Data Definition Language (DDL) command that is used to delete named schema elements such as relations/tables, constraints, or even an entire schema.