166 | Chapter 9 Enhanced Layer Functionality API Additions
queries. Custom spatial queries consist of complex and nested SQL state-
ments, making it impossible to determine which column contains the spec-
ified attribute.
For example, the following SQL statement is confusing.
SELECT (SELECT B.F_ID FROM ALLTYPES B WHERE B.F_ID=A.F_ID), A.F_ID
|| ' - ' || A.F_NAME, A.F_ID, A.F_GEOM, A.F_NAME FROM ALLTYPES A
The key column is (SELECT B.F_ID FROM ALLTYPES B WHERE
B.F_ID=A.F_ID). However, this is difficult to determine and confusing
because users are accustomed to seeing column names rather than an entire
SQL statement.
In comparison, it is much easier to determine the key column for the
following query:
SELECT F_ID, F_GEOM, F_NAME FROM ALLTYPES
It is clear that the key column is F_ID.
MGMapLayerSetup Object
The following MGMapLayerSetup methods include the new -18 (Custom
Spatial Query) error code:
■ getSDPKeyColumn
■ setSDPKeyColumn
■ getSDPKeyColumnType
■ setSDPKeyColumnType
For more information about theses methods, see the Autodesk MapGuide
Viewer API Help. You can access the MapGuide Viewer API Help by clicking
Autodesk MapGuide 6.5 ➤ Documentation ➤ Autodesk MapGuide Viewer
API Help on the Program menu.
MGDatabaseSetup Object
The following MGDatabaseSetup methods include the new -18 (Custom
Spatial Query) error code:
■ getNameColumn
■ setNameColumn
■ getUrlLinkColumn
■ setUrlLinkColumn
■ getWhereClause
■ setWhereClause
■ getSymbolAngleColumn
