The mammals database has a several thousand rows of data. But how much data does it actually have? A quick way to find out is to run our first aggregate function. Pretty much the same thing as the ...

Group By gender; # To use the group by statement, the select statement needs to have an aggregate function. if youre grouping by gender, then gender needs to be in the select statement. Select ...

Inserting NULL value in the column for GROUP BY. Re-execute the query: “NULL” in the column is considered a single group. In summary, empty or NULL entries are treated as separate groups within the ...