How To Delete Table In Sql
Contents
How do I delete a table from a SQL query?
To delete a table from the database –
- In Object Explorer, select the table you want to delete.
- Right-click the table and choose Delete from the shortcut menu.
- A message box prompts you to confirm the deletion. Click Yes, Note Deleting a table automatically removes any relationships to it.
What is used to delete a table in SQL?
Which of the following SQL commands are used to delete a tab Free 100 Questions 100 Marks 60 Mins The correct answer is Drop. Key Points
DROP – It is a Data Definition Language(DDL) Command which is used to delete, tables, views, triggers, etc from a database. A DROP statement in SQL removes a component from a relational database management system (RDBMS).
Additional Information
Data Definition Language(DDL) – Data Definition Language consists of SQL commands that can be used to define the database. List of DDL commands
Command | Description |
DROP | This command is used to delete objects from the database. |
ALTER | This is used to alter the structure of the database. |
TRUNCATE | This is used to remove all records from a table, including all spaces allocated for the records are removed |
COMMENT | This is used to add comments to the data dictionary |
RENAME | This is used to rename an object existing in the database. |
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How do I delete an empty table in SQL?
The TRUNCATE TABLE statement in SQL is a Data Definition Language (DDL) operation that labels a table’s extents for DE allocation (empty for reuse). This procedure removes all data from a table easily, usually bypassing a variety of integrity checking mechanisms.
Why truncate is faster than DELETE?
Conclusion –
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 SQL DELETE command is a DML ( Data Manipulation Language ) command that deletes existing records from the table in the database. 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.
How to delete a table in Oracle?
Use the DROP TABLE statement to move a table or object table to the recycle bin or to remove the table and all its data from the database entirely.
What is truncate a table?
Remarks – Compared to the DELETE statement, TRUNCATE TABLE has the following advantages:
Less transaction log space is used. The DELETE statement removes rows one at a time and records an entry in the transaction log for each deleted row. TRUNCATE TABLE removes the data by deallocating the data pages used to store the table data and records only the page deallocations in the transaction log. Fewer locks are typically used. When the DELETE statement is executed using a row lock, each row in the table is locked for deletion. TRUNCATE TABLE always locks the table (including a schema (SCH-M) lock) and page but not each row. Without exception, zero pages are left in the table. After a DELETE statement is executed, the table can still contain empty pages. For example, empty pages in a heap cannot be deallocated without at least an exclusive (LCK_M_X) table lock. If the delete operation does not use a table lock, the table (heap) will contain many empty pages. For indexes, the delete operation can leave empty pages behind, although these pages will be deallocated quickly by a background cleanup process.
TRUNCATE TABLE removes all rows from a table, but the table structure and its columns, constraints, indexes, and so on remain. To remove the table definition in addition to its data, use the DROP TABLE statement. If the table contains an identity column, the counter for that column is reset to the seed value defined for the column.
How to delete all table in MySQL?
Method 3: Drop All Tables in MySQL Workbench Right-click on the selected tables and select ‘Drop (n) Tables ‘ Click on Review SQL, as we will need to add in the foreign key check disable and enable.
Can we DELETE multiple tables in SQL?
Method 1: DROP Multiple Tables Using DROP –
- Before we perform the operation to drop multiple tables, let us create 2 tables in our database:
- Step 1: Creating the database.
- Query:
CREATE DATABASE db; Step 2: Set the current database as db. Query: USE DATABASE db; Step 3: Create the tables in the database. Query: CREATE TABLE A( ID INT PRIMARY KEY, Name VARCHAR(20) ); CREATE TABLE B( ID INT PRIMARY KEY, Name VARCHAR(20) ); Step 4: Dropping both tables using the DROP command. Query: DROP TABLE IF EXISTS A, B; Output: In the above image, it can be seen that on executing the command tables A and B are deleted from the database Note: IF EXISTS is used to check whether the tables are present in the database or not. We can simply use the following command also to drop the tables: DROP TABLE A, B; But it may result in an error if the tables are not present in the database. So we make use of the IF EXISTS clause.
How do I DELETE a row in MySQL?
MySQL: Delete Rows from a Table To delete rows in a MySQL table, use the DELETE FROM statement: DELETE FROM products WHERE product_id = 1 ; The WHERE clause is optional, but you’ll usually want it, unless you really want to delete every row from the table. : MySQL: Delete Rows from a Table
How do I DELETE multiple rows in SQL?
Delete all records from a table – In order to delete all data from a table, you simply need to execute the DELETE query and specify the name of the table you want to delete records from. In this case, the WHERE clause isn’t appropriate: DELETE FROM birthdays This will delete all records from the Birthdays table.
How to remove a table in MySQL query?
Use the DROP Statement to Remove a Table – To permanently remove a table, enter the following statement within the MySQL shell: DROP TABLE table1; Replace table1 with the name of the table you want to delete. The output confirms that the table has been removed.
What is the difference between DROP TABLE and DELETE table?
TRUNCATE Example – Let’s consider the table Student to understand the working of the TRUNCATE command in a better way. The execution of the above SQL Query deletes all the records from the STUDENT table, leaving only the column names. It only removes the records from the table but doesn’t remove the table from the database. The resulting table after the execution of the above SQL Query is: