Create a Query to check if any Column in a table is Null

问题

I have zero experience with SQL but am trying to learn how to validate tables. I am trying to see within a table if any of the columns are null.

Currently I have been going with a script that is just counting the number of nulls. I am doing this for each column. Is there a better script that I can use to check all the columns in a table?

select count(id) from schema.table where id is not null

If there are 100 records I would expect all columns to come back with 100 but if one column is null it will show a 0.

回答1:

You can count each column in a single query by using sum and case:

select
  sum(case when Column1 is null then 1 else 0 end) Column1NullCount
  , sum(case when Column2 is null then 1 else 0 end) Column2NullCount
  -- ...
  , sum(case when ColumnN is null then 1 else 0 end) ColumnNNullCount
from MyScheme.MyTable

来源：https://stackoverflow.com/questions/65239924/create-a-query-to-check-if-any-column-in-a-table-is-null