The database owner SID recorded in the master database differs from the database owner SID

When I try to install tSQLt onto an existing database i get the following error:

> The database owner SID recorded in the master database differs from > the database owner SID recorded in database ''. You should correct > this situation by resetting the owner of database '' using the ALTER > AUTHORIZATION statement.

This problem can arise when a database restored from a backup and the SID of the database owner does not match the owners SID listed in the master database. Here is a solution that uses the "ALTER AUTHORIZATION" statement recommended in the error message:

DECLARE @Command VARCHAR(MAX) = 'ALTER AUTHORIZATION ON DATABASE::[<<DatabaseName>>] TO 
[<<LoginName>>]' 

SELECT @Command = REPLACE(REPLACE(@Command 
            , '<<DatabaseName>>', SD.Name)
            , '<<LoginName>>', SL.Name)
FROM master..sysdatabases SD 
JOIN master..syslogins SL ON  SD.SID = SL.SID
WHERE  SD.Name = DB_NAME()

PRINT @Command
EXEC(@Command)

Added this to the top of the tSQLt.class.sql script

declare @user varchar(50)
SELECT  @user = quotename(SL.Name)
  FROM  master..sysdatabases SD inner join master..syslogins SL
    on  SD.SID = SL.SID
 Where  SD.Name = DB_NAME()
exec('exec sp_changedbowner ' + @user)

Apply the below script on database you get the error:

EXEC sp_changedbowner 'sa'

ALTER DATABASE [database_name] SET TRUSTWORTHY ON 

The simplest way to change DB owner is:

EXEC SP_ChangeDBOwner 'sa'

Necromaning:
If you don't want to use the SQL-Server 2000 views (deprecated), use this:

-- Restore sid when db restored from backup... 
DECLARE @Command NVARCHAR(MAX) 
SET @Command = N'ALTER AUTHORIZATION ON DATABASE::<<DatabaseName>> TO <<LoginName>>' 
SELECT @Command = REPLACE 
				  ( 
					  REPLACE(@Command, N'<<DatabaseName>>', QUOTENAME(SD.Name)) 
					  , N'<<LoginName>>' 
					  ,
					  QUOTENAME
					  (
						  COALESCE
						  (
							   SL.name 
							  ,(SELECT TOP 1 name FROM sys.server_principals WHERE type_desc = 'SQL_LOGIN' AND is_disabled = 'false' ORDER BY principal_id ASC )
						  )
					  )
				  ) 
FROM sys.databases AS SD
LEFT JOIN sys.server_principals  AS SL 
	ON SL.SID = SD.owner_sid 
	
	
WHERE SD.Name = DB_NAME() 

PRINT @command 
EXECUTE(@command) 
GO

Also prevents bug on oddly named database or user, and also fixes bug if no user is associated (uses sa login).