Error - 5171 Dear friend, Is it a common error that occurs due to the SQL file corruotion beucase database base corruption in SQl can afect the main file and its work process.
Why this error encounter, Once the header page or other page is not recognized by the SQL Server, then MDF file is not considered as a valid primary database file. This situation becomes the cause of SQL database error 5171
We can have two cases to solve this eroror.
Case One -Corruption in Mirrored Databases
Step 1. At first, set principal database.
Step 2. Then, modify MDF file information by using “ALTER DATABASE MODIFY FILE” command.
Step 3. Now, stop the currently running SQL server instance by clicking on the Stop option.
Step 4. After that, copy the MDF and LDF files to a different directory.
Step 5. Finally, restart the SQL Server and attach MDF and LDF files.
Case Two -Improper Upgradation of SQL Server
Solution - Run command sp_attach_db for attaching the database.
I hope it, it will help you.