The SQL **SUM** function is a built-in aggregate function in Structured Query Language (SQL) that is used to calculate the sum of a set of values in a specified column of a table. It is a powerful tool that allows you to easily compute the total of numeric data within a dataset. The SUM function returns the sum of all values from the select. Null values are ignored.

## Syntax

The syntax for the **SUM** function is as follows:

SELECT SUM(column_name) FROM table_name;

The **SUM** function works by adding up all the values in the specified column and returning the total. It can be used with any numeric data type, including integers, decimals, and floats.

### Example

For example, suppose you have a table named Training_Course that contains the following data:

**Training_Course**

ID | NAME | DURATION | PRICE |
---|---|---|---|

1 | SQL | 5 | 200 |

2 | T-SQL | 7 | 700 |

3 | MySQL | 5 | 600 |

4 | PL/SQL | 7 | 800 |

5 | PostgreSQL | 6 | 500 |

To calculate the total prices across all courses, you can use the SUM function as follows:

select SUM(PRICE) from Training_Course;

This query will return the result: 2800

In addition to the basic syntax, the **SUM** function can also be used in conjunction with other SQL functions, such as GROUP BY, HAVING, and WHERE, to calculate more complex aggregate values. It is a powerful tool that is essential for any data analyst or SQL developer working with large datasets.