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The obvious downside of this method is that a user might forget to add a COMMIT to apply the changes at the end. If the Implicit Transactions option is switched on, and the query window is simply closed, any open transactions will be rolled back (SSMS issues an IF > 0 ROLLBACK TRANSACTION statement in the background). Now, run also the DELETE statement, and note that CustomerID 1 is deleted: Open a new query, and run only the SELECT statement first to see what we are about to delete: Let’s delete some data from Sales.Customer table in AdventureWorks2014 database. To view the current setting for IMPLICIT_TRANSACTIONS, run the following query:Īfter setting IMPLICIT_TRANSACTIONS ON, always open a new query window as the setting is applied only for newly open connections, and not for the current one

In SSMS there is an option to set Implicit Transactions “ON” in SQL Server options under Tools>Options>Query Execution>SQL Server>ANSI:

When a connection is operating in implicit transaction mode, the instance of the SQL Server Database Engine automatically starts a new transaction after the current transaction is committed or rolled back. Let’s take a look at one option in SQL Server to prevent accidental data modification/loss from happening. Let’s take a look at two options in SQL Server Management Studio (SSMS) to prevent accidental data modification/loss from happening.

But we’ll explore some other tips and tricks for “safe SQL coding”. Then, just execute UPDATE or DELETE statement with the same WHERE clause. Although things like this can happen to the best of us, we can plan ahead and take preventative measures to make sure, we don’t get negatively impacted by the consequences of such a mistake.Ī good practice would be to always write a SELECT statement with a WHERE clause first and execute it to see the number of rows that will be affected. Right after we click that “Execute” button, we realize we forgot to include a WHERE clause and the entire table is wiped instead of only one row. We sometimes may find ourselves in a stressful situation at work, where for example we need to update or delete some records in our database.