How can I remove all constraints in Oracle?

How can I remove all constraints in Oracle?

2 Answers. You can do it with dynamic SQL and the data dictionary: begin for r in ( select table_name, constraint_name from user_constraints where constraint_type = ‘R’ ) loop execute immediate ‘alter table ‘|| r. table_name ||’ drop constraint ‘|| r.

How do I drop all existing tables in SQL?

If you want to use only one SQL query to delete all tables you can use this: EXEC sp_MSforeachtable @command1 = “DROP TABLE ?” This is a hidden Stored Procedure in sql server, and will be executed for each table in the database you’re connected.

How do I drop all indexes on a table?

1. INSERT INTO #commands (Command) SELECT N’ALTER TABLE ‘ + QUOTENAME(SCHEMA_NAME(o. schema_id))
2. INSERT INTO #commands (Command) SELECT ‘DROP INDEX ‘ + QUOTENAME(i. name)
3. + ‘.’ + QUOTENAME(OBJECT_NAME(s. object_id)) + ‘.’
4. OPEN result_cursor; FETCH NEXT FROM result_cursor INTO @CurrentCommand; WHILE @@FETCH_STATUS = 0.

How do you drop indexes?

DROP INDEX

1. MS Access: DROP INDEX index_name ON table_name;
2. SQL Server: DROP INDEX table_name.index_name;
3. DB2/Oracle: DROP INDEX index_name;
4. MySQL: ALTER TABLE table_name. DROP INDEX index_name;

What happens if we drop a constraint?

If you drop the constraint the data currently stored in the table is not changed but of course following DML operations can add values out of the check constraint’s range – and also NULL values if there is no additional NOT NULL constraint. There are not many situations where droping or disabling a constraint is a good idea.

How to create table constraints?

and click Design.

How does dropping column affect constraints?

If the column is part of a multiple-column primary-key or unique constraint, the constraints placed on the multiple columns are also dropped. This action, in turn, triggers the dropping of all referential constraints that reference the multiple columns. Because any constraints that are associated with a column are dropped when the column is dropped, the structure of other tables might also be altered when you use this clause.

How can we drop unique constraint from a mySQL table?

Drop Unique Constraint. The syntax for dropping a unique constraint in MySQL is: ALTER TABLE table_name DROP INDEX constraint_name; table_name The name of the table to modify. This is the table that you wish to remove the unique constraint from. constraint_name The name of the unique constraint to remove. Example