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| - | ====== Omnidex SQL Function: $DISTANCE ====== | ||
| - | ===== Description ===== | ||
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| - | The $DISTANCE function calculates the distance between one set of geographic coordinates and one or more other geographic coordinates. This is used for performing geographic radius searches, such as finding all rows within five miles of a given location. This can also be used to simply calculate the distance between two points. The following [[admin:optimization:geo:home|article]] provides more detail on performing geographic searches in Omnidex. | ||
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| - | This function returns a DOUBLE datatype. | ||
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| - | ===== Syntax ===== | ||
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| - | $DISTANCE( origin_latitude, origin_longitude, | ||
| - | destination_latitude, destination_longitude | ||
| - | [, options]) | ||
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| - | $DISTANCE( (origin_select_statement), | ||
| - | (destination_select_statement) | ||
| - | [, options]) | ||
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| - | == origin_latitude == | ||
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| - | Required. An expression containing the latitude used as the origin of this geographic search. If //origin_latitude// produces a literal string, then that origin will be used for all rows. If //origin_latitude// is a column, then the origin latitude will be treated as that value for each row processed. //Origin_latitude// can also be a select statement, enclosed in parentheses, that retrieves a latitude in a single column and a single row. Latitudes can be expressed using a FLOAT, DOUBLE, CHARACTER or C STRING datatype. | ||
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| - | == origin_longitude == | ||
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| - | Required. An expression containing the longitude used as the origin of this geographic search. If //origin_longitude// produces a literal string, then that origin will be used for all rows. If //origin_longitude// is a column, then the origin longitude will be treated as that value for each row processed. //Origin_longitude// can also be a select statement, enclosed in parentheses, that retrieves a longitude in a single column and a single row. Longitudes can be expressed using a FLOAT, DOUBLE, CHARACTER or C STRING datatype. | ||
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| - | == destination_latitude == | ||
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| - | Required. An expression containing the latitude used as the destination of this geographic search. If //destination_latitude// produces a literal string, then that destination will be used for all rows. If //destination_latitude// is a column, then the destination latitude will be treated as that value for each row processed. //Origin_latitude// can also be a select statement, enclosed in parentheses, that retrieves a latitude in a single column and a single row. Latitudes can be expressed using a FLOAT, DOUBLE, CHARACTER or C STRING datatype. | ||
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| - | == destination_longitude == | ||
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| - | Required. An expression containing the longitude used as the destination of this geographic search. If //destination_longitude// produces a literal string, then that destination will be used for all rows. If //destination_longitude// is a column, then the destination longitude will be treated as that value for each row processed. //Origin_longitude// can also be a select statement, enclosed in parentheses, that retrieves a longitude in a single column and a single row. Longitudes can be expressed using a FLOAT, DOUBLE, CHARACTER or C STRING datatype. | ||
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| - | == options == | ||
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| - | Optional. One of the options listed below: | ||
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| - | ^Option ^Description ^ | ||
| - | |MILES |Return the distance measured in miles (default) | | ||
| - | |NAUTICALMILES |Return the distance measured in nautical miles | | ||
| - | |KILOMETERS |Return the distance measured in kilometers | | ||
| - | |YARDS |Return the distance measured in yards | | ||
| - | |FEET |Return the distance measured in feet | | ||
| - | |METERS |Return the distance measured in meters | | ||
| - | |LAT_HEMISPHERE=<N | S> |Treat latitudes as in the named hemisphere | | ||
| - | |LONG_HEMISPHERE=<E | W> |Treat longitudes as in the named hemisphere | | ||
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| - | == origin_select_statement == | ||
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| - | Optional. A select statement that returns a single row containing first the latitude and then the longitude in two consecutive select-items. These pairs of coordinates represent the origin on the search. | ||
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| - | == destination_select_statement == | ||
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| - | Optional. A select statement that returns one or more rows containing first the latitude and then the longitude in two consecutive select-items. These pairs of coordinates represent the destination(s) of the search. Since //destination_select_statement// can return multiple rows, this allows geographic radius searches requesting rows within a certain distance from a number of locations, such as stores or branch offices. | ||
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| - | ===== Example ===== | ||
| - | ==== Example 1: Distance between two sets of coordinates ==== | ||
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| - | <code> | ||
| - | select $distance(40.0, -105.0, 41.0, -106.0) | ||
| - | from $omnidex | ||
| - | </code> | ||
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| - | ==== Example 2: Distance between two sets of coordinates using columns ==== | ||
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| - | <code> | ||
| - | select $distance(40.0, -105.0, latitude, longitude), | ||
| - | latitude, longitude, | ||
| - | from geo | ||
| - | where $distance(40.0, -105.0, latitude, longitude) < 10 | ||
| - | </code> | ||
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| - | ==== Example 3: Distance between two sets of coordinates using a subquery ==== | ||
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| - | <code> | ||
| - | select latitude, longitude, | ||
| - | from geo | ||
| - | where $distance((select latitude, longitude | ||
| - | from zipcodes | ||
| - | where zip = ‘80301’), | ||
| - | latitude, longitude) < 10 | ||
| - | </code> | ||
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| - | ==== Example 4: Distance between multiple sets of coordinates using a subquery ==== | ||
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| - | <code> | ||
| - | select latitude, longitude, | ||
| - | from geo | ||
| - | where $distance((select latitude, longitude | ||
| - | from zipcodes | ||
| - | where region = 'MT'), | ||
| - | latitude, longitude) < 10 | ||
| - | </code> | ||
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| - | ====== Additional Resources ====== | ||
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| - | See also: | ||
| - | {{page>dev:sql:functions:see_also_utility&noheader&nofooter&noeditbtn}} | ||
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