Wednesday, August 11, 2010

Roll back the result of truncate command

How many times it has happened that somebody asks u a difference of Truncate and Delete,Atleast i am the person who used to say the very first point is that "TRUNCATE CAN NOT BE ROLLED BACK" untill i came across the blog post of Pinal Dave

So,the best way to understand any point is start with sample,here what we will do is we will create one table and we will create one transaction and under which we will be doing our truncate thing...and finally we will observe the result

Lets us start it by creating sample table and our transaction like following as shown below


CREATE TABLE temp (Name varchar(50))
INSERT INTO temp SELECT 'Moe'
INSERT INTO temp SELECT 'Larry'
INSERT INTO temp SELECT 'Curley'


BEGIN TRAN
   SELECT * FROM temp
   TRUNCATE TABLE temp
   SELECT * FROM temp
ROLLBACK TRAN
   SELECT * FROM temp
   
DROP TABLE temp


Now if you just copy and paste this above in your query editor and hit F5 (RUN),you would be surprise to see that even if you have performed TRUNCATE operation on your table,your data are still available at the end of transaction if we ROLLBACK

I was also got the feeling of learning something new with this helpful post by Pinal,which inspired me to write this post,so that we can use it for further reference

i hope this post is larning for you people as well

comments are welcomed...:-D

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