It is well known that MS SQL database offers an administrative ease to system users by providing enhanced productivity, scalability and efficiency. It is one of the popular and extensively used databases all over the world. You can easily handle huge amount of data using this reliable database. But at the same time nobody can ignore this fact that when database becomes corrupt due to any reasons, it makes you frustrated by generating numerous irritating errors. You tried your best to resolve the errors but don’t get succeeded. One such error is SQL error 5171.

At times it happens that your system closes unexpectedly while you are working on SQL Server database. After restarting the system you are unable to open your MDF file and receives following error message:

“An exception occurred while executing a Transact-SQL statement or batch. _db.mdf is not a primary database file. (Microsoft SQL Server, Error: 5171).”

Or

“C:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\Data\MYDATABASE.mdf is not a primary database file. (Microsoft SQL Server, Error: 5171)”

Usually, users ignore SQL error 5171 and try to attach single file using sp_attach_single_db stored procedure but receive another error message. Once the error appears your SQL database becomes inaccessible and it might happen that you lose your essential data if you don’t repair it immediately. Generally the database becomes corrupt due to various adverse causes as cited below:

• Power failure
• Abrupt shut down of system
• Damaged Index
• File header corruption
• Damaged media
• Virus infections
• Human errors

All above mentioned factors can damage your SQL database and give rise to SQL error 5171. But the major reasons responsible for the error is corruption in SQL file header which might occur due to presence of invalid entries.

When the error appears it renders your database inaccessible. You can access it if you restore your database using current available backup. In the case you haven’t maintained the backup then you have to use any third party software. In order to access your database you need to repair your corrupt MDF file. You can use MS SQL Database Repair Software. It is effective software that safely repairs your corrupt indexes, tables, procedure etc and makes it accessible. The software is compatible with all versions of MS SQL like SQL Server 2000, 2005, 2008 etc.