class %SQL.FDW.Java
extends %SQL.FDW.Abstract
parameter JAVACLASS;
Class in the Foreign Table package
property Gateway
as %External.Gateway;
Object representing instance of a specific connection to the external language server
property Ptr
as %Integer;
Left in for Fetch(), which isn't how we codegen FT TVFs anyway
property ReaderObject
as %Net.Remote.Object;
method %Next(ByRef sc As %Library.Status = $$$OK)
as %Library.Integer
Advance the result set cursor to the next row. Returns 0 if the cursor is at the end of the
result set.. An optional argument contains a %Library.Status value on return. This %Status value
indicates success or failure of the %Next call. %SQLCODE is also set by %Next.
method %OnNew()
as %Status
This callback method is invoked by the %New method to
provide notification that a new instance of an object is being created.
If this method returns an error then the object will not be created.
It is passed the arguments provided in the %New call.
When customizing this method, override the arguments with whatever variables and types you expect to receive from %New().
For example, if you're going to call %New, passing 2 arguments, %OnNew's signature could be:
Method %OnNew(dob as %Date = "", name as %Name = "") as %Status
If instead of returning a %Status code this returns an oref and this oref is a subclass of the current
class then this oref will be the one returned to the caller of %New method.
method Close(StopLanguageServer As %Boolean = 0)
as %Status
Corresponds to *Close of TVF
method CreateReaderObject(Server As %String, FTClassName As %String)
as %Status
Creates an object of the class containing the functionality needed to access an external source. For now,
these will be Java objects (to read CSV/external DBs through JDBC).
1) Create request string, which is used by the external code to connect to the relevant external
source.
2) Instantiate the object, store it in ReaderObject property
Called by %SQL.FDW.Common:Execute()
method Execute(Server As %String, FTClassName As %String, Query As %String, Parameters As %List = "")
as %Status
Corresponds to the *Execute of a TVF
method Fetch(ByRef Row As %List, ByRef AtEnd As %Integer)
as %Status
Corresponds to *Fetch of a TVF
method GetRequestObject(Server As %String, FTClassName As %String)
as %DynamicObject
Build and return request string used by Reader code for connecting to a database.
For a file, Server host = abs. path to directory, Table = filename+extension, port & user & pass are all N/A
method Reset()
as %Status
Reset the result set back to the first row. Note this may entail a full re-execution depending on the specific
implmentation of the foreign data wrapper.