¿Se puede revertir Alter Table?

Can Alter Table be rolled back?

Examples of DDL include CREATE , DROP , ALTER , etc. The changes that are caused by issuing DDL commands cannot be rolled back. DML – which stands for Data Manipulation Language which lets you run select, insert, update and delete queries.

ROLLBACK ALTER column statement

1. BEGIN TRANSACTION.
2. ALTER TABLE dbo.tbl_name.
3. ADD [column1] [varchar] (20) NULL.
4. ———————————————–
5. –Error handling.
6. IF @@Error = 0.
7. Begin.
8. COMMIT TRANSACTION.

DDL and Transactions in Microsoft SQL Server This means that all these changes made by the DDL commands, that are included in the transaction, have been rolled back. So, we can include DDL commands (with some exceptions) in transactions in MS SQL Server.

Using SQL Server Management Studio

1. Right click on the database you wish to revert back to a point in time.
2. Select Tasks/Restore/Database.
3. On the restore database dialog select the Timeline option.

The SQL ALTER TABLE command is used to add, delete or modify columns in an existing table. You should also use the ALTER TABLE command to add and drop various constraints on an existing table.

COMMIT permanently saves the changes made by current transaction. ROLLBACK undo the changes made by current transaction. Transaction can not undo changes after COMMIT execution. When transaction is successful, COMMIT is applied.

3. DML(Data Manipulation Language): The SQL commands that deals with the manipulation of data present in the database belong to DML or Data Manipulation Language and this includes most of the SQL statements. Examples of DML: INSERT – is used to insert data into a table.

This script of course contains lots of DDL — CREATE TABLE, ALTER TABLE and so forth. The basic structure of it is like this: /* HOW TO USE THIS SCRIPT 1. Run it against your existing DB 2. Check whether there were any errors 3. If there were, issue a rollback by highlighting this: ROLLBACK and executing it 4.

SQLite has supported transactional DDL for many releases. MySQL has supported Atomic DDL since 8.0 (which was released in 2018). Thanks for contributing an answer to Stack Overflow!

Yes, it is possible to use many ALTER TABLE statements in one transaction with ROLLBACK and COMMIT. Here is a scaffold for your script (following MS guidelines with improvements): BEGIN TRANSACTION BEGIN TRY — place your script in this TRY block — your DDL instructions: ALTER TABLE1…

Most DDL statements can be rolled back in SQL Server (There are a few exceptions such as CREATE DATABASE) Many alterings in one transaction with rollback and commit – it is not a dream. It is possible. Here is a scaffold for your script (following MS guidelines with improvements):