Ways to Recover Data from SQL Server Transaction Log File

Summary: Many times SQL database administrator looking for ways to recover data from SQL Server Transaction logs, The user can read this article to perform this task. We have given the best possible and also the easiest way to restore data from (.ldf) file. In case you are facing database corruption issues and want to recover database objects try this Recover SQL Database Software. For further information, the user can read this article.

There are times when clients face lamentable database circumstances in their SQL Server databases. The situations could occur during the administration and support of their database files. At times the database objects are deleted unintentionally, because of which database admins face numerous issues. Subsequently, to return to the ordinary work process, the files should be recovered back to the SQL Server database.

The SQL Server Transaction Log plays a significant job in recover deleted data in the event that you erroneously play out DELETE or UPDATE operation with an inappropriate condition, or without filtration condition. This can be accomplished by listening in to the records put away inside in this black box that is known as the SQL Server Transaction Log file.

How to Recover Data from SQL Server Transaction Log File

To analyze the various techniques that we can use to recover data from the SQL Server Transaction Log file, we will create another database with a single table, utilizing the script underneath:

After creating the database and the table, we will fill that table with 30 records, utilizing the INSERT INTO T-SQL statement underneath:

Having no backup taken from the database yet, how might we recover the table’s data if the underneath UPDATE command is executed over that table with nowhere statement used to filter the data to be changed?

Utilizing Built-in Methods

1.)fn_dblog: The content of the SQL Server Transaction Log can be read online utilizing various implicit functions. The first function that we will attempt to use to recover the lost data is the fn_dblog. It is an undocumented framework table-valued function, used to make a plunge the SQL Server Transaction Log and view the content of the dynamic segment of that file.

So as to utilize the fn_dblog() function, you have to give two parameters, the beginning and the end LSN of the log. To view all logs accessible in the dynamic segment of the SQL Transaction Log file, you can pass the NULL value for these two parameters. As the outcome came back from the fn_dblog() work contains 129 columns, it is better to pick just the segments that contain the data you are keen on and filter the outcome to show just the operation that you intend to recover. For example, the LOP_INSERT_ROWS operation is logged when another record is embedded, LOP_DELETE_ROWS operation is logged when a new record is deleted, and LOP_MODIFY_ROW operation is logged when a current record is updated. The underneath script can be utilized to check the update statements that are performed on that database:

2.) fn_dump_dblog(): The subsequent framework worked in function, fn_dump_dblog(), has one advantage over the fn_dblog() work is that it very well may be utilized to read the SQL Server Transaction Log backup, notwithstanding the ability to read the online Transaction Log file. Then again, so as to utilize the fn_dump_dblog() function, you have to give 68 mandatory parameters, as appeared in the script beneath:

3.) DBCC Page Command: SQL Server gives us countless DBCC commands that can be utilized to play out the various sorts of SQL Server admin tasks. One of these undocumented commands is the DBCC Page command, which can be used to read the content of the database data and log online files. So as to see the content of the database log file, you have to give the database name and the ID of the Transaction Log file. The ID of the Transaction Log file can be recovered from the query underneath.

Limitations of Manual Methods to Recover Data from SQL Server Transaction Log

1. Difficult to Perform.
2. Requires strong Technical Knowledge.
3. High Risk of Data Loss.

Expert Solution to Recover Data from SQL Server Transaction Log File

At the point when a database is corrupted or the table’s data is erroneously lost or changed, the long-time that is required to recreate and parse the data utilizing the implicit strategies can’t be adequate. Along these lines, we need to search in the SQL Server administration market for a tool that can be effectively and immediately used to read the Transaction Log file content and show this content in an easy to use format.

SysTools SQL Log File Reader tool, that can be handily used to read the content of the online SQL Transaction Log file. By using this software the user can easily Read and Analyse the SQL Server Transactional Log files INSERT / UPDATE / DELETE operations. This Enterprise-Grade Level professional application Can work on Both offline and online database environment. Also, this application offers dynamic filters option to export a selective Transactional Log file. This software supports the SQL Server 2019 version.

Steps to Recover Data from SQL Server Transaction Log

1. Download and Install the SQL Log Analyser.

2. Now Select The Database Option

3. Preview the SQL Server Transactional Log file data.

4. Click on Export Button to Export the log file data.

Conclusion

In spite of the fact that the manual technique can recover deleted items from SQL tables, it’s not a prescribed option for clients because of its intricacy and tediousness. Rather, it is recommended to use an ideal solution to Recover Data from SQL Server Transaction Log file.