Full Answer
How to drop table in Oracle with examples?
Oracle / PLSQL: DROP TABLE Statement
- Description. The Oracle DROP TABLE statement allows you to remove or delete a table from the Oracle database.
- Syntax. The name of the schema that owns the table. ...
- Note. ...
- Example. ...
How to drop temporary table if exists in SQL Server?
- OBJECT_ID () function (all supported versions)
- Querying the sys.tables System View (all supported versions)
- Querying the INFORMATION_SCHEMA.TABLES View (all supported versions)
- DROP TABLE with IF EXISTS (SQL Server 2016 and up)
How do you delete a table in Oracle?
- Syntax.
- schema_name: It specifies the name of the schema that owns the table.
- table_name: It specifies the name of the table which you want to remove from the Oracle database.
- CASCADE CONSTRAINTS: It is optional.
How to list all tables in Oracle?
- List all Tables in Oracle Database
- How to List all Tables in Oracle Database Schema
- Display all Tables in Oracle Database
- List all User Tables In Oracle Database
- How to Find List of Tables in Oracle Database
- List all Tables and Columns in a Oracle Database
How do you drop a table only if it exists in Oracle?
DROP TABLE IF EXISTS `table_name`; This way, if the table doesn't exist, the DROP doesn't produce an error, and the script can continue. SELECT * FROM dba_tables where table_name = 'table_name'; but the syntax for tying that together with a DROP is escaping me.
How do you drop a table in Oracle?
Oracle DROP TABLEFirst, indicate the table and its schema that you want to drop after the DROP TABLE clause. ... Second, specify CASCADE CONSTRAINTS clause to remove all referential integrity constraints which refer to primary and unique keys in the table.More items...
How do you drop a table if it exists?
Option 1 - DROP TABLE if exists using OBJECT_ID() function (all supported versions) Using OBJECT_ID() will return an object id if the name and type passed to it exists.
How do you drop an existing object in Oracle?
Use the DROP TYPE statement to drop the specification and body of an object type, a varray, or a nested table type. See Also: DROP TYPE BODY for information on dropping just the body of an object type. CREATE TYPE and ALTER TYPE for information on creating and modifying types.
What is drop command in Oracle?
The DROP TABLE oracle command is used to remove a table from the database. The dropped table and its data remain no longer available for selection. Dropping a table drops the index and triggers associated with it.
How do I delete a table in Oracle SQL Developer?
To delete a table: In SQL Developer, navigate to the PURCHASE_ORDERS table in the HR schema, following the instructions in "Viewing Tables". Right-click the PURCHASE_ORDERS table and select Table and then Drop.
How do I create a drop if exists in SQL?
The ANSI SQL/cross-platform way is to use the INFORMATION_SCHEMA, which was specifically designed to query meta data about objects within SQL databases. if exists (select * from INFORMATION_SCHEMA. TABLES where TABLE_NAME = 'Scores' AND TABLE_SCHEMA = 'dbo') drop table dbo.
Why use DROP TABLE if exists?
The DROP TABLE statement deletes the specified table, and any data associated with it, from the database. The IF EXISTS clause allows the statement to succeed even if the specified tables does not exist. If the table does not exist and you do not include the IF EXISTS clause, the statement will return an error.
How do you check table is exists or not in SQL?
Using the OBJECT_ID and the IF ELSE statement to check whether a table exists or not.Query : ... Query : USE [DB_NAME] GO IF EXISTS (SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME = N'table_name') BEGIN PRINT 'Table exists.' END ELSE BEGIN PRINT 'Table does not exist.' END. ... Output :More items...•
What is purge table?
Purpose. Use the PURGE statement to remove a table or index from your recycle bin and release all of the space associated with the object, or to remove the entire recycle bin, or to remove part of all of a dropped tablespace from the recycle bin.
How do you drop a parent table?
In SQL Server, you cannot drop a table if it is referenced by a FOREIGN KEY constraint. You have to either drop the child tables before removing the parent table, or remove foreign key constraints.
How do I drop a type table in SQL?
Syntax DROP TYPE [schema.] type [ ; ] Key type Name of the type (alias or user-defined) to be dropped. When a table is dropped, all associated triggers are automatically dropped.
What happens when you drop a table in a cluster?
When you drop a table that is part of a cluster, the table is moved to the recycle bin. However, if you subsequently drop the cluster, the table is purged from the recycle bin and can no longer be recovered with a FLASHBACK TABLE operation. Dropping a table invalidates dependent objects and removes object privileges on the table.
Does a drop table release space?
Unless you specify the PURGE clause, the DROP TABLE statement does not result in space being released back to the tablespace for use by other objects, and the space continues to count toward the user's space quota.
Can you roll back a drop table?
You cannot roll back a DROP TABLE statement with the PURGE clause, nor can you recover the table if you have dropped it with the PURGE clause. Using this clause is equivalent to first dropping the table and then purging it from the recycle bin. This clause lets you save one step in the process.
How to move a table to the recycle bin?
To move a table to the recycle bin or remove it entirely from the database, you use the DROP TABLE statement: First, indicate the table and its schema that you want to drop after the DROP TABLE clause. If you don’t specify the schema name explicitly, the statement assumes that you are removing the table from your own schema.
What does the purge clause do in Oracle?
By using the PURGE clause, Oracle will not place the table and its dependent objects into the recycle bin. Notice that the PURGE clause does not allow you to roll back or recover the table that you dropped. Therefore, it is useful if you don’t want the sensitive data to appear in the recycle bin.
Option 1: Check if the Table Exists
We can check the DBA_TABLES data dictionary view to see if the table exists. This view describes all relational tables in the database. Its columns are the same as those in ALL_TABLES.
Option 2: Test for the Error
Another way to do it is to simply go ahead and run the DROP TABLE statement, and then catch any ORA-00942 error that occurs. Specifically, we catch any SQLCODE -942 error that occurs.
What is the purpose of the drop tablespace?
Purpose. Use the DROP TABLESPACE statement to remove a tablespace from the database. When you drop a tablespace, Oracle Database does not place it in the recycle bin. Therefore, you cannot subsequently either purge or undrop the tablespace.
What does "INCLUDING CONTENTS" mean in Oracle?
When you specify INCLUDING CONTENTS, the KEEP DATAFILES clause lets you instruct the database to leave untouched the associated operating system files, including Oracle-managed files. You must specify this clause if you are using Oracle-managed files and you do not want the associated operating system files removed by the INCLUDING CONTENTS clause.
Do you have to have the DROP TABLESPACE privilege?
You must have the DROP TABLESPACE system privilege. You cannot drop a tablespace if it contains any rollback segments holding active transactions.
Can you drop a tablespace that contains a domain index?
You cannot drop a tablespace that contains a domain index or any objects created by a domain index. You cannot drop an undo tablespace if it is being used by any instance or if it contains any undo data needed to roll back uncommitted transactions. You cannot drop a tablespace that has been designated as the default tablespace for the database.
Can you drop a system tablespace?
You cannot drop the SYSTEM tablespace. You can drop the SYSAUX tablespace only if you have the SYSDBA system privilege and you have started the database in MIGRATE mode. You may want to alert any users who have been assigned the tablespace as either a default or temporary tablespace. After the tablespace has been dropped, ...
Can you drop a tablespace if it has a primary key?
For example, if the tablespace being dropped contains a primary key index, but the primary key column itself is in a different tablespace, then you cannot drop the tablespace until you have manually disabled the primary key constraint in the other tablespace.