Indicates the type of query to perform. Possible values for this property are the following:
•-1 - qtUndefined: The Query object initially tries to execute the query on a Database object. If it fails, then it tries to execute the query on a Storage object. This is the default value for Queries created in E3 Studio or at run time
•0 - qtDBServer: The Query object tries to execute the query only on a Database object
•1 - qtStorage: The Query object tries to execute the query only on a Storage object
•2 - qtOpcUa: The Query object tries to execute the query only on an OPC UA Driver object
NOTES |
•When manipulating Queries at run time, it is recommended to configure this property with the desired type before performing other settings on the object, specially when reusing a Query object for different data sources. •For applications created on previous versions, when opening the application in E3 Studio this property is automatically configured to -1 - qtUndefined. •The AddStorageTag and RemoveStorageTag methods fail if this property is configured to 0 - qtDBServer. •The FunctionType property does not accept the value -1 - ftNoFunction if this property is configured to 1 - qtStorage. •The AddField, AddTable, and RemoveTable methods fail if this property is configured to 1 - qtStorage. •If this property is configured to -1 - qtUndefined, an attempt to execute the Query on a Storage object (after the Query fails on a Database object) fails if the FunctionType property is configured to -1 - ftNoFunction or if the FunctionSubType property is configured to an invalid value. |