Common Query Language (CQL2)

The Common Query Language (CQL2) Standard is a generic filter grammar that can be used to specify how resource instances in a source collection of any item type, including features, can be filtered to identify a results set. Typically, CQL2 is used in query operations to identify the subset of resources, such as features, that should be included in a response document. However, CQL2 can also be used in other operations, such as updates, to identify the subset of resources that should be affected by an operation.

CQL2 specifies:

• A JSON encoding for the grammar.
• A filter grammar;
• A text encoding for the grammar;