Uses of the GROUP BY Function

When retrieving data from the database, we can group rows using the GROUP BY statement.

Basic use of GROUP BY

The GROUP BY function is used as part of a SELECT statement:

SELECT ColumnName FROM TableSchema.TableName
GROUP BY ColumnName;

In this basic form, GROUP BY allows us to see the distinct values in a given column. In some cases, this approach is much more effective in terms of performance compared to the DISTINCT keyword. The reason is that DISTINCT is applied to the whole query while GROUP BY eliminates the duplicates first and then performs the rest of the work. In the code below, we use GROUP BY to print out the names of teams that are participating in the competition: