How to change a column without dropping a table in SQL 2008

Question

Why does SQL 2008 all of a sudden want to drop my tables when I go to change the column type from say int to real? This never happened in SQL 2005 to my knowledge. Any insight

Answer 1

Here is what I use:

-- Add new column
ALTER TABLE MyTable
ADD Description2 VARCHAR(MAX)
GO

-- Copy data to new column (probably with modifications)
Update MyTable
SET Description2 = Description
GO

-- Drop old column
ALTER TABLE MyTable
DROP COLUMN Description
GO

-- Rename new column to the original column's name.
sp_RENAME 'MyTable.Description2' , 'Description', 'COLUMN'
GO

1. Copy the data into a new column.
2. Drop the old column.
3. Rename the new column to the old column's name.