How can I solve "Either the parameter @objname is ambiguous or the claimed @objtype (COLUMN) is wrong."? [duplicate]

Nuts. I hit this same error weeks ago, and after a lot of wasted time figured out how to make it work--but I've since forgotten it. (Not much help, other than to say yes, it can be done.)

Have you tried different combinations of brackets, or of with and without brackest? e.g.

EXEC sp_rename 'ENG_TEst.ENG_Test_A/C_TYPE', 'ENG_Test_AC_TYPE', 'COLUMN';
EXEC sp_rename '[ENG_TEst].[ENG_Test_A/C_TYPE]', 'ENG_Test_AC_TYPE', 'COLUMN';
EXEC sp_rename '[ENG_TEst].[ENG_Test_A/C_TYPE]', '[ENG_Test_AC_TYPE]', 'COLUMN';
EXEC sp_rename '[ENG_TEst].ENG_Test_A/C_TYPE', 'ENG_Test_AC_TYPE', 'COLUMN';

If all else fails, there's always

• Create new table (as "xENG_TEst") with proper names
• Copy data over from old table
• Drop old table
• Rename new table to final name

This works

EXEC sp_rename 
@objname = 'ENG_TEst."[ENG_Test_A/C_TYPE]"', 
@newname = 'ENG_Test_A/C_TYPE', 
@objtype = 'COLUMN'

Are you running the query in the correct database? i.e.,

Use MyDatabase;
GO
EXEC sp_rename 'ENG_TEst.[ENG_Test_A/C_TYPE]', 'ENG_Test_AC_TYPE', 'COLUMN';
GO

I ran into this today and got it to work with:

EXECUTE sp_rename N'dbo.table_name.original_field_name', N'new_field_name', 'COLUMN' 

To get this syntax, I followed Martin Smith's advice above - open up the table in design view, rename the column and then click table designer | generate change script. This produced the script below which does the renaming in two steps:

/* To prevent any potential data loss issues, you should review this script in
   detail before running it outside the context of the database designer.*/
BEGIN TRANSACTION
SET QUOTED_IDENTIFIER ON
SET ARITHABORT ON
SET NUMERIC_ROUNDABORT OFF
SET CONCAT_NULL_YIELDS_NULL ON
SET ANSI_NULLS ON
SET ANSI_PADDING ON
SET ANSI_WARNINGS ON
COMMIT
BEGIN TRANSACTION
GO
EXECUTE sp_rename N'dbo.table_name.original_field_name', N'Tmp_new_field_name_1', COLUMN' 
GO
EXECUTE sp_rename N'dbo.table_name.Tmp_new_field_name_1', N'new_field_name', 'COLUMN' 
GO
ALTER TABLE dbo.table_name SET (LOCK_ESCALATION = TABLE)
GO
COMMIT