In 2005, an object's owner is schema owner by default. It can be changed to other principals by "ALTER AUTHORIZATION", in this case, the principal_id will not be null i the sys.objects table. To get table (view, SP,udf, etc) owner:

SELECT

o.object_id, o.name,

CASE WHEN principal_id is NOT NULL THEN (SELECT name FROM sys.database_principals dp WHERE dp.principal_id=o.principal_id)

ELSE (SELECT dp.name FROM sys.database_principals dp,sys.schemas s WHERE s.schema_id=o.schema_id and s.principal_id=dp.principal_id)

END as Owner

FROM

sys.objects o

WHERE

type='U'

GO

E.g.:

USE AdventureWorks

GO

select

* FROM sys.objects where type='U'

select

* from sys.schemas

SELECT

* from sys.database_principals

GO

SELECT o.object_id, o.name,

CASE WHEN principal_id is NOT NULL THEN (SELECT name FROM sys.database_principals dp WHERE dp.principal_id=o.principal_id)

ELSE (SELECT dp.name FROM sys.database_principals dp,sys.schemas s WHERE s.schema_id=o.schema_id and s.principal_id=dp.principal_id)

END as Owner

FROM

sys.objects o

WHERE

type='U'

GO

Change one table owner to guest:

ALTER

AUTHORIZATION ON Production.ProductSubcategory TO guest

GO

SELECT o.object_id, o.name,

CASE WHEN principal_id is NOT NULL THEN (SELECT name FROM sys.database_principals dp WHERE dp.principal_id=o.principal_id)

ELSE (SELECT dp.name FROM sys.database_principals dp,sys.schemas s WHERE s.schema_id=o.schema_id and s.principal_id=dp.principal_id)

END as Owner

FROM

sys.objects o

WHERE

type='U'

GO

Restore the table owner to schema owner:

ALTER

AUTHORIZATION ON Production.ProductSubcategory TO schema owner

GO