Ordering Allergies by Popularity from Patient Records
Your task is to write an SQL query to fetch all allergies from the patients
table. The data should be ordered by the popularity of each allergy. Ensure you exclude any NULL values from your result.
Concepts to Remember
-
Grouping and Aggregating: In many cases, we're interested not just in the individual rows of a table, but in aggregations of rows. The
GROUP BY
clause groups rows that have the same values in specified columns into summary rows. -
Ordering Results: The order in which rows are returned in a result set can be specified using the
ORDER BY
clause. You can sort the results by a column in ascending or descending order. -
Filtering Data: The
WHERE
clause is used to filter records based on specific conditions. Pay attention to how you can use it to exclude specific values, such as NULL.
The column names must be allergies
and total_diagnosis
Good luck with your query!