Question

If I have a table with columns A through C (this is just an example) and I have many entries that populates these tables, entries may be Null

ex:

A | B | C
1 | 2 | 6
1 | 4 | Null
1 | 0 | Null

how can i write a query that woulld output:
– My column names as rows
– a count of number of null entries for each column
– a minimun / maximum / average for each column

i.e:

A | 0 | 1 | 1 | 1
B | 0 | 0 | 4 | 2
C | 2 | 6 | 6 | 2

where

• 2nd column is the number of NULL entries
• 3rd is the minimum
• 4th is the max
• 5th is an average of all entries for that column

I apprecaite any help you can give me!!

Answer 1

write three queries, each GROUPed BY a single column, and produce the data needed for the column in the query

be sure to add the columnName as a literal in the SELECT statements

UNION the three queries together and order by columnName

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EDIT:

another option would be to push columnName and value to a temp table for each column and then the query with the aggregate functions becomes simple…

CREATE #tempTable (columnName, columnValue)

INSERT INTO #tempTable
SELECT 'A', A
FROM whatever

use a spreadsheet to create your 50 INSERT statements, and then, as I said above, the aggregate query should be simple