Count the Null columns in a row in SQL

Question

I was wondering about the possibility to count the null columns of row in SQL, I have a table Customer that has nullable values, simply I want a query that return an int of

Answer 1

My answer builds on Michael Berkowski's answer, but to avoid having to type out hundreds of column names, what I did was this:

Step 1: Get a list of all of the columns in your table

SELECT COLUMN_NAME FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = 'myTable';

Step 2: Paste the list in Notepad++ (any editor that supports regular expression replacement will work). Then use this replacement pattern

• Search:

  ^(.*)$
  

• Replace:

  \(CASE WHEN \1 IS NULL THEN 1 ELSE 0 END\) +
  

Step 3: Prepend SELECT identityColumnName, and change the very last + to AS NullCount FROM myTable and optionally add an ORDER BY...

SELECT 
    identityColumnName, 
    (CASE WHEN column001 IS NULL THEN 1 ELSE 0 END) +
    -- ...
    (CASE WHEN column200 IS NULL THEN 1 ELSE 0 END) AS NullCount
FROM
    myTable
ORDER BY 
    NullCount DESC