SQL Aggregate Functions |
SQL Sample Code - SQL Aggregate Functions. |
| SELECT function_type(column_name) FROM table_name; |
See the SQL Samples section below for an explanation.
What do SQL Aggregate Functions do? |
SQL aggregate functions return a value calculated from the values in a specified column. Such as adding a column’s values together or getting the average value of a given column.
The most commonly used Aggregate Functions are:
COUNT( ) - Returns the number of rows
AVG( ) - Returns the average value
SUM( ) - Returns the sum
FIRST( ) - Returns the first value
LAST( ) - Returns the last value
MAX( ) - Returns the largest value
MIN( ) - Returns the smallest value
SQL Sample 1 – SQL SUM() Function |
In this SQL sample we will use the database table ‘tblCompany’.
| Company_ID | CompanyName | Address | Town | Sales |
| 1 | SQL Sample | 1 Sample St | Hamburg | 10000 |
| 2 | SQL Code Land | 2 Code Rd | Hamburg | 20000 |
| 3 | Sample Code World | 66 SQL St | Curry | 18000 |
| 4 | SQL Reference Ltd | 34 Reference St | Pisa | 17000 |
In this SQL sample we want to know the total SUM() for the Sales column in the tblCompany table.
Use the SELECT statement below:
| SELECT SUM(Sales) AS Total_Sales FROM tblCompany; |
The result will look like this:
| Total_Sales |
| 65000 |
Note: the AS operator is used to name the result column as ‘Total_Sales’. See the Alias section of this website to learn more about renaming database columns and tables.
SQL Sample 2 – SQL SUM() Function using GROUP BY. |
In this SQL sample we will use the database table ‘tblCompany’.
| Company_ID | CompanyName | Address | Town | Sales |
| 1 | SQL Sample | 1 Sample St | Hamburg | 10000 |
| 2 | SQL Code Land | 2 Code Rd | Hamburg | 20000 |
| 3 | Sample Code World | 66 SQL St | Curry | 18000 |
| 4 | SQL Reference Ltd | 34 Reference St | Pisa | 17000 |
In this SQL sample we want to know the total SUM() for the Sales column in the tblCompany table for each Town.
Use the SELECT statement below:
| SELECT Town, SUM(Sales) FROM tblCompany GROUP BY Town; |
The result will look like this:
| Town | SUM(Sales) |
| Hamburg | 30000 |
| Curry | 18000 |
| Pisa | 17000 |
Related SQL Sample Code:
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