Ordnance Survey MasterMap Topography Layer

A dataset that views Ordnance Survey (GB) Digital National Framework (DNF) data, e.g. Ordnance Survey MasterMap, stored in a relational database.


Dataset Item Properties


  • Cadcorp SIS Desktop
  • Cadcorp SIS Desktop Express
  • Cadcorp SIS ActiveX Modeller
  • Cadcorp SIS ActiveX Manager
  • Cadcorp SIS ActiveX Viewer
  • Cadcorp GeognoSIS

Dataset Properties

  • Angle column: _angleColumn$
    The column in the database table containing the rotation angle for shapes/text.

  • Attributes: _attributes$
    A list of attributes held by the dataset.

  • Class name: _class$
    The class name of the dataset.

  • Coordinate Reference System: _projection$
    The dataset Coordinate Reference System in Open Geospatial Consortium (OGC) Well-Known-Text format. (Notice that some SIS Coordinate Reference System objects are not supported in OGC.)

  • Editable: _bEditable&
    Is the dataset editable?

  • Feature Code column: _fcodeColumn$
    The dataset column whose values should be used as the item Feature code.

  • Feature table: _featureTable$
    The Feature Table which dataset items with no Feature Table of their own use when their Feature code is set. This Feature Table is also used to get information about available feature codes, and to create a default Feature Filter.

    N.B. This does not override the Feature Table on an item.

  • Filtered: _bFiltered&
    A boolean value indicating whether the dataset is filtered.

  • Layers: _layers$
    The set of all values the Layer property for all items in the dataset.

  • Maximum number of open Gateways: _nMaxGatewayOpen&
    The maximum number of Gateway sub-datasets a dataset should attempt to open simultaneously.

  • Modified: _bModified&
    Has the dataset been modified?

  • Name: _name$
    The dataset name. For a file-based dataset this will be the filename.

  • Next item id: _idNextItem&
    The Item ID which will be used for the next Item created in this dataset.

  • Notes: _notes$
    User notes on dataset.

  • Number of Items: _nItems&
    The number of items in the dataset.

  • Scale: _scale#
    The dataset scale.

  • Size: _size&
    The amount of memory, in bytes, that the dataset uses.

  • Transactions: _bTransact&
    Does the database-based dataset use transactions?

  • uriColumn: _uriColumn$
    The column in the database table containing data which is accessible via the URI property.

Dataset Item Properties

  • Bookmark: _bookmark$
    Cursor-based datasets have the concept of a bookmark. Any item in a cursor-based dataset will have this property, which lets you go back to the underlying data store and find the row. For example, use GetStr(SIS_OT_DATASET, 0, "_bookmark$") or the SetStr (SIS_OT_DATASET, 0, "_bookmark$") to get and set the bookmark value for Oracle datasets.