Supported filter languages¶
Data filtering in GeoServer is based on the concepts found in the OGC Filter Encoding Specification.
GeoServer accepts filters encoded in two different languages: Filter Encoding and Common Query Language.
The Filter Encoding language is an XML-based method for defining filters. XML Filters can be used in the following places in GeoServer:
- in WMS GetMap requests, using the filter parameter
- in WFS GetFeature requests, using the filter parameter
- in SLD Rules, in the Filter element
The Filter Encoding language is defined in the following OGC specifications:
CQL (Common Query Language) is a plain-text language created for the OGC Catalog specification. GeoServer has adapted it to be an easy-to-use filtering mechanism. GeoServer actually implements a more powerful extension called ECQL (Extended CQL), which allows expressing the full range of filters that OGC Filter 1.1 can encode. ECQL is accepted in many places in GeoServer:
- in WMS GetMap requests, using the cql_filter parameter
- in WFS GetFeature requests, using the cql_filter parameter
- in SLD dynamic symbolizers
The CQL and ECQL languages are defined in: