# MI_AggregateBuffer

## Description

Returns a MultiPolygon geometry object which represents a buffered distance around the aggregated geometry objects.

## Syntax

MI_AggregateBuffer ( geometry, dist, unit, calculationType, res )

## Arguments

`geometry` is an expression which returns a geometry,

`dist` is a number which represents the distance from the source geometry for the buffer,

`unit` is an area unit specification,

`calculationType` is a string that indicates whether to perform a Spherical or Cartesian calculation. There is no default, and

`res` is a number which specifies the minimum number of segments used in creating a circle from buffering a point.

## Example

Returns a MultiPolygon geometry object which represents a buffered distance around the aggregated geometry objects.

`select MI_AggregateBuffer([Geometry_Column],5,'km','Spherical',10) from countries where country in ('Canada','United States','Mexico')`

## Remarks

Valid values for `unit` are the following distance units:

Value | Description |
---|---|

mi | miles |

km | kilometers |

in | inches |

ft | feet |

yd | yards |

mm | millimeters |

cm | centimeters |

m | meters |

survey ft | US Survey feet |

nmi | nautical miles |

twip | twips |

pt | points |

pica | picas |

degree | degrees |

li | links |

ch | chains |

rd | rods |