MQL5 ReferenceConstants, Enumerations and StructuresTrade Constants History Database PropertiesOrder PropertiesPosition PropertiesDeal PropertiesTrade Operation TypesTrade Transaction TypesTrade Orders in DOMSignal Properties Trade Constants Various constants used for programming trading strategies are divided into the following groups: History Database Properties – receiving general information on a symbol; Order properties – obtaining information about trade orders; Position properties – obtaining information about current positions; Deal properties – obtaining information about deals; Trade operation types – description of trade operations available; Trade transaction types - description of possible trade transactions types; Trade orders in DOM – separation of orders according to the direction of a requested operation. Testing Statistics History Database Properties