There is no 'DROP TABLE IF EXISTS' in oracle, you would have to do the select statement. One way is to use DBMS_ASSERT. SQL_OBJECT_NAME : This function verifies that the input parameter string is a qualified SQL identifier of an existing SQL object.
In this regard, how do I drop a table in Oracle?
Introduction to Oracle DROP TABLE statement
- First, 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.
Furthermore, how do you check if a table exists in Oracle? You can also check the data dictionary to see if a table exists: SQL> select table_name from user_tables where table_name='MYTABLE'; Another way to test if a table exists is to try to drop the table and catch the exception if it does not exist.
Beside this, what happens when we drop a table in Oracle?
When you drop a table, normally the database does not immediately release the space associated with the table. Rather, the database renames the table and places it in a recycle bin, where it can later be recovered with the FLASHBACK TABLE statement if you find that you dropped the table in error.
How do you permanently delete a table in Oracle?
Oracle DROP TABLE statement is used to remove or delete a table from the Oracle database.
- 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.
Similar Question and The Answer
Does drop table free up space Oracle?
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. For an external table, this statement removes only the table metadata in the database.
Can we drop a table with primary key?
Drop Primary Key In SQL, you can drop a primary key using the ALTER TABLE statement.
What is the difference between delete and truncate?
DROP and TRUNCATE are DDL commands, whereas DELETE is a DML command. Therefore DELETE operations can be rolled back (undone), while DROP and TRUNCATE operations cannot be rolled back. TRUNCATE can be rolled back if wrapped in a transaction.
What is Purge command in Oracle?
PURGE. 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.
Do we need commit after drop table?
CREATE TABLE and DROP TABLE statements do not commit a transaction if the TEMPORARY keyword is used. (This does not apply to other operations on temporary tables such as ALTER TABLE and CREATE INDEX , which do cause a commit.)
What is drop database?
The DROP DATABASE Statement is used to drop or delete a database. Dropping of the database will drop all database objects (tables, views, procedures etc.) inside it. The user should have admin privileges for deleting a database. The DROP statement cannot be rollback.
Can we drop a column with data in Oracle?
Oracle Drop Column using SET UNUSED COLUMN clause SET UNUSED COLUMN column_name; DROP UNUSED COLUMNS; If you want to reduce the amount of undo logs accumulated, you can use the CHECKPOINT option that forces a checkpoint after the specified number of rows has been processed.
How do I drop all tables in a schema in Oracle?
If you need to drop all tables in the database with Oracle, here's an easy way! run this command: select 'drop table ', table_name, 'cascade constraints;' from user_tables; Then copy the output and run that as a sql script.
What is drop table?
Drop a Table. The drop table command is used to delete a table and all rows in the table. Deleting all of the records in the table leaves the table including column and constraint information. Dropping the table removes the table definition as well as all of its rows.
What happens to a trigger if a table is dropped?
Dropping a table invalidates dependent objects and removes object privileges on the table. If you want to re-create the table, then you must regrant object privileges on the table, re-create the indexes, integrity constraints, and triggers for the table, and respecify its storage parameters.
Can we drop a table with foreign key?
SQL Server - Drop All References to 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.
Is synonym dropped when table is dropped?
2 Answers. Dropping a table invalidates objects which have a dependency on the table: those views, synonyms and procedures are not dropped but cannot be used until we intervene to make them compile (e.g. by editing the source code).
Does Drop Table Delete Index?
DROP TABLE removes tables from the database. DROP TABLE always removes any indexes, rules, triggers, and constraints that exist for the target table. However, to drop a table that is referenced by a view or a foreign-key constraint of another table, CASCADE must be specified.
How do you drop a synonym in Oracle?
Introduction to Oracle DROP SYNONYM statement First, specify the name of the synonym that you want to remove after the DROP SYNONYM keyword. If the synonym belongs to a schema, you must specify its schema name. Second, use the FORCE keyword to delete the synonym even if it has dependent tables or user-defined types.