XC (TQL)
Instead of specifying a clause parameter with a particular Item ID, it is possible to use the 'XC' characters for its value. The result of using 'XC' for the clause value, is the automatic creation of multiple TQL statements, one with each Item ID for that Clause Parameter, but only the Items that are covered by the calculated Search Polygon of the TQL statement. The Search Polygon is calculated by overlapping the clause polygon. Per clause type it is indicated if it limits the 'Search Polygon'. Internally, the resulting TQL statements are placed in a single array; Similarly the result will be an array of TQL results.
Example
Consider the following (simplified) Neighborhood data of a project:
[ {
"id" : 0, "name" : "East Side",
"polygons" : { "type" : "MultiPolygon", "coordinates" : [ [ [ [ 250.0, -500.0 ], [ 500.0, -500.0 ], [ 500.0, 0.0 ], [ 250.0, 0.0 ], [ 250.0, -500.0 ] ] ] ] }
}, {
"id" : 1, "name" : "West Side",
"polygons" : { "type" : "MultiPolygon", "coordinates" : [ [ [ [ 0.0, -500.0 ], [ 250.0, -500.0 ], [ 250.0, 0.0 ], [ 0.0, 0.0 ], [ 0.0, -500.0 ] ] ] ] }
} ]and the Area data:
[ {
"id" : 0, "name" : "Upper Left",
"polygons" : { "type" : "MultiPolygon", "coordinates" : [ [ [ [ 110.0, -110.0 ], [ 110.0, -100.0 ], [ 100.0, -100.0 ], [ 100.0, -110.0 ], [ 110.0, -110.0 ] ] ] ] }
}, {
"id" : 1, "name" : "Upper Right",
"polygons" : { "type" : "MultiPolygon", "coordinates" : [ [ [ [ 435.0, -95.0 ], [ 425.0, -95.0 ], [ 425.0, -105.0 ], [ 435.0, -105.0 ], [ 435.0, -95.0 ] ] ] ] }
}, {
"id" : 2, "name" : "Lower Left",
"polygons" : { "type" : "MultiPolygon", "coordinates" : [ [ [ [ 165.0, -425.0 ], [ 165.0, -415.0 ], [ 155.0, -415.0 ], [ 155.0, -425.0 ], [ 165.0, -425.0 ] ] ] ] }
}, {
"id" : 3, "name" : "Lower Right",
"polygons" : { "type" : "MultiPolygon", "coordinates" : [ [ [ [ 315.0, -395.0 ], [ 325.0, -395.0 ], [ 325.0, -385.0 ], [ 315.0, -385.0 ], [ 315.0, -395.0 ] ] ] ] }
} ]The TQL statement
SELECT_NAME_WHERE_AREA_IS_XC_AND_NEIGHBORHOOD_IS_0
is internally replaced with a list of TQL statements, separated by comma's,
SELECT_NAME_WHERE_AREA_IS_1_AND_NEIGHBORHOOD_IS_0, SELECT_NAME_WHERE_AREA_IS_3_AND_NEIGHBORHOOD_IS_0
Its result will be a list of names, separated by comma's, for example:
"Upper Right", "Lower Right"
Clause Parameters
The XC value can be used in the following TQL Clause parameters: