Replace empty cells with NULL values in large number of columns

Question

I have SQL table that has a large number of columns. For some reason, some columns have empty cells instead of NULL cells. I would like to make all empty cells in all the column

Answer 1

You could do a query on syscolumns to get a list of columns, and use the results to construct your query.

select quotename(name) + ' = nullif (' + quotename(name)+ ','''')'
from syscolumns 
where id = object_id('yourtable')

Additionally, if you write your query as

update yourtable
set
    yourcolumn=nullif(yourcolumn, ''),
    yourcolumn2=nullif(yourcolumn2, ''),
    ...    

then you can do it in a single query without a where clause