SQL Progressive (one) GROUP by clause

GROUP BY clause

First, you talk about the GROUP BY clause syntax:

SELECT Column1, SUM (Column2)

From "List-of-tables"

GROUP by "column-list";

This GROUP BY clause sets all the rows together, it contains the data for the specified column, and allows the aggregate function to compute one or more columns. The best way to explain this, of course, is to give an example:

Let's say we're going to search the employee table for the highest-paid column, and you can use the following SQL statement:

SELECT Max (Salary), Dept

From employee

GROUP by dept;

This statement will select the highest salary in each individual department. As a result their salary and dept will be returned.