What is the difference between drop and truncate commands in SQL?

Question

What is the difference between drop and truncate commands in SQL? Please let me know if there is any functional changes in this.

Amit Mohanty · Answer

In SQL, the "DROP" and "TRUNCATE" commands are used to remove data from database tables, but they have different functionalities and implications: DROP Command : The DROP command is used to remove an entire table or other database objects, such as views, indexes, or procedures, from the database. When you execute a DROP command on a table, it permanently removes the table structure along with all its data, indexes, constraints, and triggers. This action cannot be undone, and the table must be recreated if you want to use it again. TRUNCATE Command : The TRUNCATE command is used to remove all rows from a table, but it preserves the table structure. Unlike the DROP command, the TRUNCATE command only deletes data and does not remove the table itself or any associated objects like indexes, constraints, or triggers. The table structure remains intact, and you can continue using the table after truncation. Functional Differences: The DROP command removes the entire table and its associated objects, while the TRUNCATE command removes only the data within the table, leaving the table structure intact. When you drop a table, you need to recreate it if you want to use it again, including all its associated objects. Truncated tables can be used immediately after the truncation operation. Dropping a table cannot be rolled back, and the data is permanently deleted. Truncating a table can be rolled back within a transaction if the database supports transactional operations. The DROP command may require additional privileges or permissions depending on the database system, whereas TRUNCATE typically requires only the necessary table-level permissions. It's essential to use these commands carefully since they have irreversible consequences for data and database objects. Always ensure you have a backup or a comprehensive understanding of the potential impact before executing these commands.

Brahma Prakash Shukla · Answer

the main difference between the DROP and TRUNCATE commands in SQL is that DROP deletes the entire table, including the structure, whereas TRUNCATE only removes the data within the table while preserving the table structure.

Vishal Yelve · Answer

What is the DROP Command in SQL? The SQL DROP command is a DDL (Data Definition Language) command that deletes the defined table with all its table data, associated indexes, constraints, triggers, and permission specifications. The DROP command drops the existing table from the database. It only requires the name of the table to be dropped. Syntax DROP TABLE table_name; What is the DELETE Command in SQL? The SQL DELETE command is a DML (Data Manipulation Language) command that deletes existing records from the table in the database. It can delete one or more rows from the table depending on the condition given with the WHERE clause. Thus the deletion of data is controlled according to the user's needs and requirements. The DELETE statement does not delete the table from the database. It just deletes the records present inside it and maintains a transaction log of each deleted row. Syntax DELETE FROM TableName WHERE condition; What is the TRUNCATE Command in SQL? The SQL TRUNCATE command is a DDL (Data Definition Language) command that modifies the data in the database. The TRUNCATE command helps us delete the complete records from an existing table in the database. It resets the table without removing it from the database. It does not use the WHERE clause like the DELETE command to apply the condition. It requires the table name to delete the records. It has faster performance due to the absence of conditions checking. Syntax TRUNCATE TABLE table_name; DELETE Command DROP Command TRUNCATE Command Language The DELETE command is Data Manipulation Language Command. The DROP command is Data Definition Language Command. The TRUNCATE command is a Data Definition Language Command. Use The DELETE command deletes one or more existing records from the table in the database. The DROP Command drops the complete table from the database. The TRUNCATE Command deletes all the rows from the existing table, leaving the row with the column names. Transition We can restore any deleted row or multiple rows from the database using the ROLLBACK command. We cannot get the complete table deleted from the database using the ROLLBACK command. We cannot restore all the deleted rows from the database using the ROLLBACK command. Memory Space The DELETE command does not free the allocated space of the table from memory. The DROP command removes the space allocated for the table from memory. The TRUNCATE command does not free the space allocated for the table from memory. Performance Speed The DELETE command performs slower than the DROP command and TRUNCATE command as it deletes one or more rows based on a specific condition. The DROP Command has faster performance than DELETE Command but not as compared to the Truncate Command because the DROP command deletes the table from the database after deleting the rows. The TRUNCATE command works faster than the DROP command and DELETE command because it deletes all the records from the table without any condition. Integrity Constraints The Integrity Constraints remain the same in the DELETE command. The Integrity Constraints get removed for the DROP command. The Integrity Constraints will not get removed from the TRUNCATE command. Permission DELETE permission is required to delete the rows of the table. We need ALTER permission on the schema to which the table belongs and CONTROL permission on the table to use the DROP command. We need table ALTER permission to use the TRUNCATE command. Syntax DELETE FROM table_name WHERE condition; DROP TABLE table_name; TRUNCATE TABLE table_name; Drop Examples- DROP TABLE Employee; Delete Examples- DELETE FROM Employee WHERE EmployeeId = 10001; Truncate Examples- TRUNCATE TABLE Employee;

Rajkiran Swain · Answer

In SQL, both the DROP and TRUNCATE commands are used to remove data from a table, but they have some key differences: 1. DROP Command: - The DROP command is used to delete an entire table from the database. - When you use the DROP command, all the data, structure, indexes, constraints, and triggers associated with the table are permanently removed. - Once a table is dropped, it cannot be recovered unless you have a backup. - The syntax for the DROP command is: `DROP TABLE table_name;` 2. TRUNCATE Command: - The TRUNCATE command is used to remove all the data from a table, but the table structure, indexes, constraints, and triggers remain intact. - TRUNCATE is faster than DELETE for removing all data from a table because it does not generate individual log entries for each deleted row. - Like the DROP command, TRUNCATE is a DDL (Data Definition Language) operation. - Once a table is truncated, the data is permanently deleted, and it cannot be recovered unless you have a backup. - The syntax for the TRUNCATE command is: `TRUNCATE TABLE table_name;` In summary, the main difference between DROP and TRUNCATE is that DROP deletes the entire table along with its structure, while TRUNCATE removes all the data from the table but keeps the table structure intact. If you only want to remove data from a table and retain the table structure, TRUNCATE is generally the preferred choice due to its performance advantage.

Aradhana Tripathi · Answer

DROP command is used to remove the whole table structure or table indexes, data, and more. The important part of this command is that it has the ability to permanently remove the table and its contents whereas TRUNCATE command is used to remove all the rows from the table. However, the structure of the table and columns remains the same. It is faster than the DROP command. You can refer below article to understand with examples. https://www.c-sharpcorner.com/article/difference-between-delete-truncate-and-drop-statements-in-sql-server If you got your answer, kindly mark it as accepted.

Janarthanan S · Answer

DROP command is used to drop the entire table including structure and its associated data. TRUNCATE command is used to remove all the rows from the table but the structure remains the same.

Konga Mounika · Answer

Hi sir, The main difference between the DROP and TRUNCATE commands in SQL is that DROP permanently removes a table from the database, while TRUNCATE removes all data from a table but keeps the table structure intact and also It's important to note that the functional outcome of using either command is the removal of data. However, the impact and consequences differ in terms of permanence, speed, recoverability, and associated objects.

Jayanta Mukherjee · Answer

The DROP command is used to remove an entire table from the database. When you use the DROP command, all the data, indexes, and privileges associated with the table are removed. The TRUNCATE command is used to remove all the data from a table, but it does not remove the table structure or its associated indexes. When you use the TRUNCATE command, all the data in the table is deleted, but the table structure remains intact. Regarding "Functional Changes", there are some functional changes between the DROP and TRUNCATE commands. The main difference is that the DROP command removes the entire table, including its structure, while the TRUNCATE command only removes the data from the table. This means that if you use the DROP command, you will need to recreate the table and its associated indexes if you want to use it again. On the other hand, if you use the TRUNCATE command, you can still use the table structure and its associated indexes. Another difference between the two commands is that the DROP command is a DDL (Data Definition Language) command, while the TRUNCATE command is a DML (Data Manipulation Language) command. This means that the DROP command is used to modify the structure of the database, while the TRUNCATE command is used to modify the data in the database.

Bikesh Srivastava · Answer

DROP Vs. TRUNCATE: Explore the Major Differences between DROP and TRUNCATE. In SQL, the DROP command is used to remove the whole database or table indexes, data, and more. Whereas the TRUNCATE command is used to remove all the rows from the table.

Aravind Govindaraj · Answer

In simple terminology, DROP means deleting the schema, however truncate does only delete all the records in the specified schema.

Anandu G Nath · Answer

@Dhanush K DROP Command : DROP is used to delete an entire table, including its structure (columns, constraints, indexes, etc.). When you execute the DROP command on a table, the table itself is removed from the database and cannot be recovered. It removes the table and all its data, and the table definition is entirely eliminated from the database schema. Syntax DROP TABLE my_table; TRUNCATE Command : TRUNCATE is used to delete all rows from a table, but it retains the table structure. Unlike DROP , TRUNCATE doesn’t delete the table itself; it only removes the data inside the table, leaving the table structure intact. It's faster than DELETE as it doesn’t generate individual row delete operations but instead deallocates the data pages and only resets the identity value if there's any. TRUNCATE is generally less resource-intensive compared to DELETE as it doesn’t log individual row deletions. Syntax TRUNCATE TABLE my_table;

Subarta Ray · Answer

The main difference between the SQL DROP and TRUNCATE commands is their purpose. DROP removes an entire table, including its structure, while TRUNCATE retains the table structure but deletes all rows. DROP is more drastic and cannot be rolled back, while TRUNCATE can be rolled back within a transaction. Functionally, DROP eliminates the table entirely, affecting metadata, permissions, and dependencies, whereas TRUNCATE only removes data. Use DROP when the entire table needs elimination; use TRUNCATE for efficient deletion of data while keeping the table structure intact.