cql_filter 和 bbox互斥

cql_filter和bbox是两种不同的查询参数，它们并不互斥。CQL_FILTER是一种过滤器，它可以用于过滤WMS或WFS服务返回的要素。而bbox则是一种空间查询参数，用于指定查询的地理范围。这两种参数可以一起使用，用于更精确的查询结果。例如，可以使用bbox参数指定查询的地理范围，同时使用CQL_FILTER参数指定要素的其他属性条件，以过滤符合条件的要素并返回结果。

相关问题

cql_filter BBOX

BBOX是一种用于过滤地理坐标范围的cql_filter函数。它接受4个参数：最小经度、最小纬度、最大经度和最大纬度，用逗号分隔。例如，以下cql_filter函数将选择位于经度-120至-110，纬度30至40之间的所有要素：

cql_filter=BBOX(the_geom,-120,30,-110,40)

该函数可用于在地图中显示特定区域的要素，或者搜索位于特定地理区域内的要素。

cql_filter

CQL (Common Query Language) filter is a query language used in Geospatial Information Systems (GIS) to filter and retrieve specific data from a dataset based on certain criteria. It is commonly used in mapping applications and geospatial databases.

CQL filters allow you to define queries using logical expressions and comparison operators to select features or objects that meet specific conditions. These filters can be used to query attributes, spatial relationships, or a combination of both.

For example, a CQL filter can be used to retrieve all the cities within a certain distance from a given location, or all the buildings with a specific height range.

The syntax for a CQL filter is typically written as a string and can vary depending on the GIS software or database system you are using. It usually consists of attribute names, comparison operators (such as "=", "<", ">"), logical operators (such as "AND", "OR", "NOT"), and values.

Here's an example of a CQL filter in the context of searching for cities within a specific distance:

distance(geometry, POINT(x, y)) <= radius

In this example, `geometry` represents the location of the city, `x` and `y` represent the coordinates of the center point, and `radius` represents the maximum distance from the center point.

I hope this helps! Let me know if you have any more questions.