# DWithin

## Description

Determines if a geometry (testGeometry) object is located inside a perimeter distance from another geometry (containerGeometry) object.

## Syntax

DWithin ( testGeometry, containerGeometry, unit, distance )

## Arguments

`containerGeometry` and `testGeometry` are geometry objects (or expressions),

`distance` is a number (double) which represents the determining distance from the source geometry to the test geometry, and

`unit` is an area unit specification.

## Example

Determines if one of the specified countries is located within a 10 miles boundary of the area defined using a box.

`select DWithin([Geometry_Column],MI_Box(-13.36676789,8.05796847,79.06334219,62.70540978,'epsg:4326'), "mi", 10) as theResult from countries where country = ANY ('Mauritania','Mali','Algeria')`

## Remarks

Returns true if `testGeometry` is within the specified distance from `containerGeometry`, false otherwise. If either `containerGeometry` or `testGeometry` are null, false is returned. The function is performed using the coordinate system of the (`containerGeometry`).

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 |