ArcGIS Pro 3.1 API Reference Guide
ArcGIS.Core.Data Namespace / Database Class / GetQueryDescription Method / GetQueryDescription(String,String) Method
A valid SQL SELECT statement that describes how the query layer should be created.
A given name.
Example

In This Topic
    GetQueryDescription(String,String) Method
    In This Topic
    Gets the QueryDescription object associated with the query layer that is created from one or more database table(s) as specified by queryStatement. This method must be called on the MCT. Use QueuedTask.Run.
    Syntax
    Public Overloads Function GetQueryDescription( _
       ByVal queryStatement As String, _
       ByVal queryLayerName As String _
    ) As QueryDescription

    Parameters

    queryStatement
    A valid SQL SELECT statement that describes how the query layer should be created.
    queryLayerName
    A given name.

    Return Value

    The QueryDescription object that fully describes how the underlying database table(s) that make up the query layer should be represented as a Table or FeatureClass if the query layer is spatially enabled.
    Exceptions
    ExceptionDescription
    queryStatement or queryLayerName is null or an empty string.
    A database-related exception has occurred.
    Remarks
    A QueryDescription object fully describes how a single database table or one or more database tables (specified by a valid SQL SELECT statement) should be represented as a Table or FeatureClass if the table is spatially enabled. Essentially, there are two flavors of QueryDescription. The first is created by this method. Given a valid SQL SELECT statement and a query layer name, it encapsulates all the important properties that describe the underlying query layer that is created from one or more tables (i.e., QueryDescription.IsQueryLayer returns true). The second flavor is created by GetQueryDescription(String). Given a table name (fully qualified or unqualified), it encapsulates all the important properties that describe the underlying single table (i.e., QueryDescription.IsQueryLayer returns false).
    Example
    Create QueryDescription from a custom query for a Database table
    public async Task CustomQueryDescription()
    {
      await ArcGIS.Desktop.Framework.Threading.Tasks.QueuedTask.Run(() =>
      {
        DatabaseConnectionProperties databaseConnectionProperties = new DatabaseConnectionProperties(EnterpriseDatabaseType.SQLServer)
        {
          AuthenticationMode = AuthenticationMode.DBMS,
          Instance = "instance",
          Database = "database",
          User = "user",
          Password = "password"
        };
    
        using (Database database = new Database(databaseConnectionProperties))
        {
          QueryDescription queryDescription = database.GetQueryDescription("SELECT OBJECTID, Shape, FACILITYID FROM EmergencyFacility WHERE JURISDICT = 'Municipal'", "MunicipalEmergencyFacilities");
    
          using (Table table = database.OpenTable(queryDescription))
          {
            // Use the table.
          }
        }
      });
    }
    Create QueryDescription from a join query where there is no non-nullable unique id column
    public async Task JoinQueryDescription()
    {
      await ArcGIS.Desktop.Framework.Threading.Tasks.QueuedTask.Run(() =>
      {
        DatabaseConnectionProperties databaseConnectionProperties = new DatabaseConnectionProperties(EnterpriseDatabaseType.SQLServer)
        {
          AuthenticationMode = AuthenticationMode.DBMS,
          Instance = "instance",
          Database = "database",
          User = "user",
          Password = "password"
        };
    
        using (Database database = new Database(databaseConnectionProperties))
        {
          QueryDescription queryDescription = database.GetQueryDescription("SELECT BUSLINES.ID as BUSLINESID, BUSSTOPS.ID as BUSSTOPSID, BUSLINES.RTE_DESC, BUSLINES.DIR, BUSSTOPS.JURISDIC, BUSSTOPS.LOCATION, BUSSTOPS.ROUTE,BUSSTOPS.SHAPE from demosql.dbo.BUSSTOPS JOIN demosql.dbo.BUSLINES ON BUSSTOPS.ROUTE = BUSLINES.ROUTE", "BusInfo");
    
          queryDescription.SetObjectIDFields("BUSLINESID,BUSSTOPSID");
    
          using (Table table = database.OpenTable(queryDescription))
          {
            // Use the table.
          }
        }
      });
    }
    Create QueryDescription from a query for a Database table which has more than one shape type
    public async Task MultiGeometryQueryDescription()
    {
      await ArcGIS.Desktop.Framework.Threading.Tasks.QueuedTask.Run(() =>
      {
        DatabaseConnectionProperties databaseConnectionProperties = new DatabaseConnectionProperties(EnterpriseDatabaseType.SQLServer)
        {
          AuthenticationMode = AuthenticationMode.DBMS,
          Instance = "instance",
          Database = "database",
          User = "user",
          Password = "password"
        };
    
        using (Database database = new Database(databaseConnectionProperties))
        {
          QueryDescription pointQueryDescription = database.GetQueryDescription("select Description, SHAPE, UniqueID from MULTIGEOMETRYTEST", "MultiGeometryPoint");
          pointQueryDescription.SetShapeType(GeometryType.Point);
          using (Table pointTable = database.OpenTable(pointQueryDescription))
          {
            //use pointTable
          }
    
          QueryDescription polygonQueryDescription = database.GetQueryDescription("select Description, SHAPE, UniqueID from MULTIGEOMETRYTEST", "MultiGeometryPolygon");
          polygonQueryDescription.SetShapeType(GeometryType.Polygon);
          using (Table polygonTable = database.OpenTable(polygonQueryDescription))
          {
            //use polygonTable
          }
        }
      });
    }
    Create QueryDescription from a query for an SQLite Database table
    public async Task SqliteQueryDescription()
    {
      await ArcGIS.Desktop.Framework.Threading.Tasks.QueuedTask.Run(() =>
      {
        using (Database database = new Database(new SQLiteConnectionPath(new Uri("Path\\To\\Sqlite\\Database\\USA.sqlite"))))
        {
          QueryDescription washingtonCitiesQueryDescription = database.GetQueryDescription("select OBJECTID, Shape, CITY_FIPS, CITY_NAME, STATE_FIPS, STATE_CITY, TYPE, CAPITAL from main.cities where STATE_NAME='Washington'", "WashingtonCities");
    
          using (Table washingtonTable = database.OpenTable(washingtonCitiesQueryDescription))
          {
            // Use washingtonTable.
          }
        }
      });
    }
    Requirements

    Target Platforms: Windows 11, Windows 10

    ArcGIS Pro version: 3.0 or higher.
    See Also