To find the total salary of all the employees:Īs we can see, the count function on “Dept_ID” returns the total number of records in the table, and the sum function on “Salary” returns the arithmetic sum of all the employees’ salaries. Let’s see what happens when we use an aggregate function without the GROUP BY statement.The above query will result in the following: The WHERE clause will be applied to the rows before they are grouped. To find the maximum salary for each department with “Dept_ID” greater than 1003: The WHERE clause can also be used in the query, and it precedes the GROUP BY statement.To find the number of employees from each city, this is what is required:Īnd it will result in the following table:Īs we can see, the groups have been ordered in ascending order, according to the number of employees from each city. Let’s see what happens when we use the ORDER BY clause.There was no ORDER BY clause, so the table has no definite order of rows. We have used the AVG() aggregate function for this purpose. In this table, to find the average salary for each department’s employees, we’ll use the following query:.Let’s take a sample “Employee_dept” table: Let’s apply the concepts stated above to the columns of a table to get an even clearer picture of the Group By statement. MIN(): From a group of values, returns the minimum value.MAX(): From a group of values, returns the maximum value.SUM(): Calculates the arithmetic sum of the set of numeric values.AVG(): Calculates the average of the set of values.The five aggregate functions that we can use with the SQL Order By statement are: NOTE: The ORDER BY statement always appears after the GROUP BY statement and is applied to the groups of rows formed.Īggregate functions are one of the most vital parts of the SQL Group By statement, so let’s see what these are. The optional ORDER BY statement is used to sort the resulting table in ascending order based on the column specified in this statement's column_name parameter.The GROUP BY statement lets the database system know that we wish to group the same value rows of the columns specified in this statement's column_names parameter.NOTE: The WHERE clause always precedes the ORDER BY statement. There is an optional WHERE clause, which can be used to specify any condition according to which the rows are to be selected.The table being used is specified in the table_name parameter of the FROM statement.Any of the aggregate functions can be used on one or more than one of the columns being retrieved. The columns to be retrieved are specified in the SELECT statement and separated by commas.To better understand how SQL Order By is used, let’s get an insight into this statement's syntax. The SUM() aggregate function, which results in the arithmetic sum of the rows’ values, has been applied to the groups in the above illustration. Combine: The values are combined in a single row.Apply: The aggregate function is applied to the values of these groups.Split: The different groups are split with their values.The SQL Group By statement uses the split-apply-combine strategy. This statement is used with the SELECT command in SQL. Generally, these functions are one of the aggregate functions such as MAX() and SUM(). The Group By statement is used to group together any rows of a column with the same value stored in them, based on a function specified in the statement. This is an essential statement in SQL as it provides us with a neat dataset by letting us summarize important data like sales, cost, and salary. Group By in SQL helps us club together identical rows present in the columns of a table. SQL allows the user to store more than 30 types of data in as many columns as required, so sometimes, it becomes difficult to find similar data in these columns.