Question

A number of times over the last month I’ve had to replace ‘null’ fields with ‘0’ to every column returned from a query.

to save a lot of time (some of these are returning a high number of columns) I’ve been using the following and then pasting the results for relevant columns into a new query:

select      ',  isnull(' + COLUMN_NAME + ', 0)' + ' as ' + COLUMN_NAME
from        INFORMATION_SCHEMA.COLUMNS
where       TABLE_NAME = 'summary_by_scca_sales_category '
            and TABLE_SCHEMA = 'property''

Essentially I’m wondering if there’s a better way that I can do this? Ideally a method where I could automatically apply isnull to all columns being returned in a query (without using two queries).

For example:

I want to take a query like:

select  *
from    tablename

And for every column returned by * replace null results with 0 without having to write an isnull() line for each column.

edit:

Will accomplish this with a view (doh, should have thought of that). For interests / educations sake is there a way to do something like this with code also?

Answer 1

You could create a VIEW against the tables in question where the ISNULL logic you want is set up. Then queries against the views would return the data you want.

EDIT:

As requested, some sample code to accomplish creating the VIEWs automatically. This is pretty gross, but for something that only has to be run once it will work. Beware of type issues (you stated everything should transmute to 0 so I assume all your columns are of a suitable numeric type):

DECLARE @table_def varchar(max)
SET @table_def = 'CREATE VIEW <tname>_NoNull AS SELECT '

SELECT @table_def = REPLACE(@table_def, '<tname>', t.name) + 
    'ISNULL(' + c.name + ', 0) AS ' + c.name + ', '
FROM sys.tables t
    INNER JOIN sys.columns c ON t.object_id = c.object_id
WHERE t.name = <<table name>>

SELECT @table_def