Question

Here is the scenario.
I’m writing my geo-ruby oracle adapter for Ruby On Rails which supports working with SDO_GEOMETRY out of box.
It was going well. I wrote codes for selecting SDO_GEOMETRY objects from Oracle DB successfully.
Everything ruins up when I wanted to write insert and update parts.
Following is what’s in my mind. I want to be able to do this statement:

g = GeoShape.new(name:"point1", shape: Point.from_x_y(-34,-43,4326))
g.save

I generated following sql query from the above statements:

INSERT INTO "GEO_SHAPES" ("CREATED_AT", "ID", "NAME", "SHAPE", "UPDATED_AT") VALUES (:a1, :a2, :a3, :a4, :a5)  [["created_at", Tue, 03 Jul 2012 08:42:01 UTC +00:00], ["id", 10112], ["name", "point1"], ["shape", "SDO_GEOMETRY(2001,  NULL, NULL, SDO_ELEM_INFO_ARRAY(1,1,1), SDO_ORDINATE_ARRAY(-34,-43))"], ["updated_at", Tue, 03 Jul 2012 08:42:01 UTC +00:00]]

But execution of above query gave me this error:

ActiveRecord::StatementInvalid: OCIError: ORA-00932: inconsistent datatypes: expected MDSYS.SDO_GEOMETRY got CHAR

I got into oracle_enhanced_adapter to trace the problem. I tried to monkey patch it and manually initialize binds[3][1] (which is the value of sdo_geometry column in my DB) as follows:

    def exec_insert(sql, name, binds)
    log(sql, name, binds) do
      returning_id_index = nil
      cursor = if @statements.key?(sql)
        @statements[sql]
      else
        @statements[sql] = @connection.prepare(sql)
      end

    binds[3][1] = "SDO_GEOMETRY(2001,  NULL, NULL, SDO_ELEM_INFO_ARRAY(1,1,1), SDO_ORDINATE_ARRAY(-34,-43))" ### DAVE

      binds.each_with_index do |bind, i|
        col, val = bind
        if col == :returning_id
          returning_id_index = i + 1
          cursor.bind_returning_param(returning_id_index, Integer)
        else
          if val == "SDO_GEOMETRY(2001,  NULL, NULL, SDO_ELEM_INFO_ARRAY(1,1,1), SDO_ORDINATE_ARRAY(-34,-43))" ### DAVE
            cursor.bind_param(i + 1, val, OCI8::Object::Mdsys::SdoGeometry) ###DAVE
          else ### DAVE
            cursor.bind_param(i + 1, type_cast(val, col), col && col.type)
          end
        end
      end

      cursor.exec_update

Unfortunately, it didn’t help. I still got the same error ORA-00932.
Any ideas? It’s so critical for me to fix this.

P.S: ###DAVE parts are my monkey patches of oracle_enhanced_adapter.rb
P.S: Here is my config.

• Oracle 11.2
• Ruby version 1.9.3 (i386-darwin11.3.0)
• Rails version 3.2.5
• Active Record version 3.2.5

Answer 1

Finally, I managed to fix the problem.
Enhanced adapter uses bind_param method to perform binding variables to their appropriate oracle types. Here was the problem and error.
I had to override some codes in oracle_enhanced_adpter.rb.
I add a method to this file to manually build a SDO_GEOMETRY object.
Then I bind this returned object to OCI8::Object::Mdsys::SdoGeometry type.

My method contains these codes (Now, only for creating SDO_GEOMETRY Points):

#I needed a connection to my oracle database. Connection placeholder is conn.
def create_sdo_geometry_object(conn, gtype, srid, point, x, y)
    local_cursor = conn.parse("BEGIN :geom := SDO_GEOMETRY(:sdo_gtype, :sdo_srid, :sdo_point, :sdo_elem_info_array, :sdo_ordinate_array); END;")
    local_cursor.bind_param(:sdo_gtype, OraNumber)
    local_cursor.bind_param(:sdo_srid, OraNumber) 
    local_cursor.bind_param(:sdo_point, OCI8::Object::Mdsys::SdoPointType) 
    local_cursor.bind_param(:sdo_elem_info_array, OCI8::Object::Mdsys::SdoElemInfoArray)
    local_cursor.bind_param(:sdo_ordinate_array, OCI8::Object::Mdsys::SdoOrdinateArray)

    local_cursor.bind_param(:geom, OCI8::Object::Mdsys::SdoGeometry)

    sdo_gtype = OraNumber.new(gtype)
    sdo_srid = OraNumber.new(srid)
    sdo_point = nil #Temporarily I set it to nil


    #sdo_elem_info_array must be [1,1,1] for creating points.
    sdo_elem_info_array = OCI8::Object::Mdsys::SdoElemInfoArray.new(conn,OraNumber.new(1),OraNumber.new(1),OraNumber.new(1))
    #I want to create a point with x and y coordinates
    sdo_ordinate_array = OCI8::Object::Mdsys::SdoOrdinateArray.new(conn,OraNumber.new(x),OraNumber.new(y))

    local_cursor[:sdo_gtype] = sdo_gtype
    local_cursor[:sdo_srid] = sdo_srid
    local_cursor[:sdo_point] = sdo_point
    local_cursor[:sdo_elem_info_array] = sdo_elem_info_array
    local_cursor[:sdo_ordinate_array] = sdo_ordinate_array
    local_cursor.exec

    local_cursor[:geom]
end

Then when I wanted to bind this parameter I used the following code:

cursor.bind_param(i + 1, create_sdo_geometry_object("PARAMS HERE"), OCI8::Object::Mdsys::SdoGeometry)

It worked like a charm!