Microsoft SQL Server Spatial

Microsoft 2008 SQL Server Spatial provides the ability to store, edit and access spatial data.

SIS Desktop 9 supports loading data into the database whilst also allowing a multi-user environment with concurrent editing.

Microsoft SQL Server 2008 conforms to OpenGIS Simple Features Specification.

Spatial data will be stored in the GEOMETRY data type. This is a "Flat Earth" or planar data type which uses map coordinate reference system units.

SIS Desktop 9 does not support the GEOGRAPHY data type.

This is a cursor-based dataset.


  1. Microsoft SQL Server does not recognise columns with unsigned integer types. Therefore Cadcorp SIS Desktop creates any such columns as signed values. In addition, Decimal columns are created as NUMERIC, with a default numeric scale if both the precision and numeric scale are zero.
  2. TEXT, NTEXT and IMAGE data types will be removed in a future version of Microsoft SQL Server and should therefore not be used. VARCHAR(MAX), NVARCHAR(MAX) and VARBINARY(MAX) will replace them respectively.

Arguments to CreateDataSourceOverlay API Method

  • clsDataSource$


  • params$

[Connection=string] - the full ADO connection string.
[Filter=string] - optional

Dataset Properties

Dataset Item Properties


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

Dataset Properties

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

  • Cached: _bCached&
    The dataset is read into SIS in cached mode. See What is a Spatial Database? - Cached Mode.

  • 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.)

  • Current Catalog: _currentCatalog$
    The name of the current database catalog.

  • 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.

    Note: This does not override the Feature Table on an item.

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

  • Geometry column: _geometryColumn$
    The column in a dataset containing the geometry of the item.

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

  • Limit hint: _limitHint&
    The maximum number of Items to use when drawing or annotating from a SQL-enabled Dataset (NB a hint only)

  • 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.

  • Order hint: _orderHint$
    The order in which to draw or annotate Items a SQL-enabled Dataset, as a SQL ORDER BY clause. e.g. 'priority ASC' (NB a hint only)

  • SQL WHERE expression: _where$
    The SQL WHERE expression in a dataset's recordset.

  • Scale: _scale#
    The dataset scale.

  • Server: _server$
    The name, or IP address, of the server host.

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

  • Table/Data Source: _dataSource$
    The database table containing the data for the dataset.

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

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

  • User name: _user$
    The username used in the connection to the database.

  • bReadOnly: _bReadOnly&
    The dataset is read-only.

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 SQL datasets.