VirtualTable
Represents a Virtual Table.
This interface declares the mandatory functions required by SQLite as well as the optional ones. An optional function F must be implemented only if the VirtualTableModule that instantiated a VirtualTable returned the function F when VirtualTableModule.optionalFunctions was called. Otherwise, the function F do not need to be implemented and is guaranteed to never been called by SQLite.
If an error is detected in a mandatory or optional function, and if error raising is allowed by SQLite, it is allowed to raise an SQLiteException that is then reported to SQLite.
The errMsg is internally filled with the SQLiteException's message when one is thrown by a function. So unless the implementation do not want to deal with exceptions, it is not required to fill it.
The nRef and errMsg properties must only be accessed from within one of the methods listed in VirtualTable. So it is illegal to access these fields in one of VirtualTableModule methods as an example.
Properties
Functions
This method is used by SQLite to determine the best way to access the virtual table.
Releases the connection to the virtual table without destroying the backing store, if any.
Returns a ScalarFunction that overrides the global one identified by name and argumentCount. If the function should not be overridden, then null is returned.
Creates a new cursor for accessing the virtual table.
Updates the virtual table and returns the newly inserted rowid or null if no rowid must be returned to SQLite.