When it is desired to summarize data within a table, an aggregate query can be created. An aggregate query is an SQL statement that uses an aggregate function to gather information from multiple rows. An aggregate function is a function that performs calculations on a column in a set of rows. When this query is executed, a result set with the summary information is produced in a single row.

An example of when an aggregate function could be used would be to produce a total value of an inventory. This would be accomplished with the SUM function being applied to a price column.

The following aggregate functions are available:

Aggregate Function | Description |

AVG | Average of values in a column. |

COUNT | Counts how many rows. |

MAX | Maximum value in a column. |

MIN | Minimum value in a column. |

STDEV | Sample standard deviation of the values in a column. |

STDEVP | Standard deviation of the values in a column. |

SUM | Adds the values in a column. |

VAR | Sample variance of the values in a column. |

VARP | Variance of the values in a column. |