StandaloneTableDescription
Base Type: MapTableDescription
A class that provides access to the available properties of a table description object.
Property |
Type |
Description |
---|---|---|
DefinitionExpression |
string |
It can be set on a layer or a standalone table in order to limit rows available for query. |
ID |
int |
The unique id of standalone table. |
Source |
Data source for dynamic table. | |
SourceID |
string |
Not in use currently. |
TimeDataCumulative |
bool |
Indicates if time is cumulative. |
TimeDataCumulativeSpecified |
bool |
Indicates if TimeDataCumulative is specified. |
TimeOffset |
double |
The time offset. |
TimeOffsetSpecified |
bool |
Indicates if TimeOffset is specified. |
TimeOffsetUnits |
The time units of the offset. | |
TimeOffsetUnitsSpecified |
bool |
Indicates if TimeOffsetUnits is specified. |
UseTime |
bool |
Indicates if table uses time. |
UseTimeSpecified |
bool |
Indicates if UseTime is specified. |
Remarks
This object represents each standalone table available in the map. When obtained from the MapServerInfo.StandaloneTableDescriptions property, this is usually used with query functions to get rows which meet criteria provided by a client.
DefinitionExpression:
The StandaloneTableDescription includes a DefinitionExpression. A DefinitionExpression can be set on a standalonetable in order to limit table rows available for query. This only applies for the request and does not replace the definition query set in the source map. A standalonetable can have a default definition expression that is set for that table in the source map.
When UseStandardizedQueries is True:
- the DefintionExpression of a StandaloneTableDescription retrieved from MapServerInfo.StandaloneTableDescriptions is always empty regardless of whether a definition expression set to the layer in the source map.
- an expression set in the StandaloneTableDescription will be appended to the one set for the table in the source map.
- you can only use StandardizedQueries. This means you will always format a query on a date field the same way or if you want to find all features where the value in a string field contains a specified keyword, you can use the same function name regardless of the underlying database type. Queries containing anything specific to the underlying database, for example, a function that is only supported by the database but is not part of the StandardizedQueries specification will fail.
When UseStandardizedQueries is False:
- a StandaloneTableDescription can have a default definition expression that is set for that table in the source map.
- an expression set in the StandaloneTableDescription will override the one set for the table in the source map.
- the query must conform to the underlying database's syntax and use functions supported by that database
Please make sure to check MapServerInfo::SupportsDynamicLayers value is True before setting Source. If it is False, the Source property is ignored.