In my legacy database, a lot of the time the schema needlessly allows null entries for particular columns. To help find out which columns in particular, I need to do some querying of SQL Server 2008 that beyond my level of expertise. My aim is to tighten up the schema a bit and save myself from dealing with the null case in my code.
A crude way (option 1) to help me solve my problem is to just get all records (and select *) that contain at least one null entry, then eye scan for columns that contain no null entries. I could of course just use
Where columnA IS NULL OR columnB IS NULL OR columnC IS NULL, but this gets tedious for tables with lots of columns. Some tables in this database contain more than twenty columns! Also, there's about 500 tables in total. So, general solutions are best.
Here are three options for answers that would satisfy me:
- Option 1 : "get me all the records where at least one of the columns is null". I will eyescan for columns with no null entries.
- Option 2 : An even better answer would be some script that gets a list of column names that contain at least one null entry. Then I will see which nullable columns are not in this list manually.
- Option 3: The best answer would get me a list of column names that are marked as nullable in their schema even though no records exist with a null entry in those columns.