Error 3154: The backup set holds a backup of a database other than the existing database.

What is this below error

Error 3154: The backup set holds a backup of a database other than the existing database.

Connect to the SSMS >take the DB backup of AdventureWorksDW-

So I have taken to the C:Drive as shown below-

So when you are start restoring of this database Backup file to the active database I,e TestDB you will get the below error(see below).

So to resolve this issue you may required to use the below query-

RESTORE DATABASE [TestDB] FROM  DISK = N'C:\ADWK.BAK' WITH  FILE = 1,  MOVE N'AdventureWorksDW_Data' TO N'C:\t1.mdf',  MOVE N'AdventureWorksDW_Log' TO N'C:\t2.ldf',  NOUNLOAD,  REPLACE,  STATS = 10

GO

Output will be

10 percent processed.

20 percent processed.

30 percent processed.

40 percent processed.

50 percent processed.

60 percent processed.

70 percent processed.

80 percent processed.

90 percent processed.

100 percent processed.

Processed 8760 pages for database 'TestDB', file 'AdventureWorksDW_Data' on file 1.

Processed 2 pages for database 'TestDB', file 'AdventureWorksDW_Log' on file 1.

RESTORE DATABASE successfully processed 8762 pages in 2.047 seconds (35.065 MB/sec).

If didn’t works then you may required to drop and re-create with backup file.