After you apply the “Alter Table” T-SQL or Transaction-SQL command to modify a column that is not null to null, you may get incorrect results. The problem occurs if the database column is a clustered index key in SQL Server. Furthermore, you may face any of the given corruption symptoms:

  • You get records that have null columns.
  • A database has marked as suspect. Furthermore, the database becomes unavailable. In the Server error log, you find runtime errors that look like the following:

spid58 Error: 644, Severity: 21, State: 1
spid58 could not find the index entry for RID ‘360000000002000101000f00383136′ in index page (1:77); index ID 0, database ‘testdb’.

spid58 Error: 3314, Severity: 21, State: 4
spid58 Error while undoing logged operation in database ‘testdb’. Error at log record ID (5:141:239).
spid58 Error: 9001, Severity: 21, State: 1
spid58 the log for database ‘testdb’ is not available.
spid58 Error: 3314, Severity: 21, State: 5
spid58 Error while undoing logged operation in database ‘testdb’. Error at log record ID (5:32:1).
spid17 Database ‘testdb’ (database ID 18) could not recover. Contact Technical Support.

  • When you run dbcc checkdb command, you will get corruption errors.

Reasons of the problem

There are two possible reasons of this issue:

  • Syscolumns and sysindexes system tables are damaged
  • A column is the part of the clustered index key that might be null

It is the critical situation of SQL Server database corruption that requires being resolved as soon as possible.
How to fix it

You can resolve the issue only by repairing the damaged database. You can repair the database of MDF file by using the SQL Recovery software. SQL recovery are the third party applications designed for MDF repair in all critical situations of MDF corruption.

MDF recovery software are fairly easy to use and the SQL repair can be carried out by user itself without having any sound technical knowledge. The effective SQL recovery software can perform complete MDF repair and the else case can worse the scenario.

Stellar Phoenix SQL Database Recovery is the best ever made and easy to use SQL recovery software that is applicable in each case of MDF corruption. Using this MDF repair software, you can repair and restore all of the SQL server objects such as tables, reports, macros, stored procedures, user defined data types, defaults and many others.