ArcGIS Pro 3.0 API Reference Guide
ArcGIS.Core.Data Namespace / QueryDef Class / SubFields Property
Example

In This Topic
    SubFields Property (QueryDef)
    In This Topic
    Gets or sets a comma (,) delimited string containing the names of fields for which values should be returned by the query.
    Syntax
    public string SubFields {get; set;}
    Public Property SubFields As String
    Remarks

    The default setting for subfields is to request values to be returned for all fields. The strings of "*" or "" can be set to return the query to this default.

    To set the subfields property to request the values to be returned for the "Name" and "Age" fields, a string of "Name, Age" should be provided (white space is optional).

    Example
    Evaluating a QueryDef on a Join using WHERE Clause
    public async Task JoiningWithWhereQueryDef()
    {
      await ArcGIS.Desktop.Framework.Threading.Tasks.QueuedTask.Run(() =>
      {
        using (Geodatabase geodatabase = new Geodatabase(new DatabaseConnectionFile(new Uri("path\\to\\sde\\file"))))
        {
          QueryDef municipalEmergencyFacilitiesQueryDef = new QueryDef
          {
            SubFields = "EmergencyFacility.OBJECTID, EmergencyFacility.Shape, EmergencyFacility.FACILITYID, FacilitySite.FACILITYID, FacilitySite.FCODE",
            Tables = "EmergencyFacility, FacilitySite",
            WhereClause = "EmergencyFacility.FACNAME = FacilitySite.NAME AND EmergencyFacility.JURISDICT = 'Municipal'",
          };
    
          using (RowCursor rowCursor = geodatabase.Evaluate(municipalEmergencyFacilitiesQueryDef, false))
          {
            while (rowCursor.MoveNext())
            {
              using (Row row = rowCursor.Current)
              {
                Feature feature = row as Feature;
                Geometry shape = feature.GetShape();
    
                long objectID = Convert.ToInt64(row["EmergencyFacility.OBJECTID"]);
                String featureCode = Convert.ToString(row["FacilitySite.FCODE"]);
    
                IReadOnlyList<Field> fields = feature.GetFields(); //Contains one ArcGIS.Core.Data.Field objects for every subfield
              }
            }
          }
        }
      });
    }
    Evaluating a QueryDef on a OUTER JOIN
    public async Task EvaluatingQueryDefWithOuterJoin()
    {
      await ArcGIS.Desktop.Framework.Threading.Tasks.QueuedTask.Run(() =>
      {
        using (Geodatabase geodatabase = new Geodatabase(new DatabaseConnectionFile(new Uri("path\\to\\sde\\file"))))
        {
          QueryDef queryDefWithLeftOuterJoin = new QueryDef
          {
            Tables = "CommunityAddress LEFT OUTER JOIN MunicipalBoundary on CommunityAddress.Municipality = MunicipalBoundary.Name",
            SubFields = "CommunityAddress.OBJECTID, CommunityAddress.Shape, CommunityAddress.SITEADDID, CommunityAddress.ADDRNUM, CommunityAddress.FULLNAME, CommunityAddress.FULLADDR, CommunityAddress.MUNICIPALITY, MunicipalBoundary.Name, MunicipalBoundary.MUNITYP, MunicipalBoundary.LOCALFIPS",
          };
    
          using (RowCursor rowCursor = geodatabase.Evaluate(queryDefWithLeftOuterJoin, false))
          {
            while (rowCursor.MoveNext())
            {
              using (Row row = rowCursor.Current)
              {
                Feature feature = row as Feature;
                Geometry shape = feature.GetShape();
    
                int siteAddressId = Convert.ToInt32(row["CommunityAddress.SITEADDID"]);
                String stateName = Convert.ToString(row["MunicipalBoundary.name"]);
              }
            }
          }
        }
      });
    }
    Evaluating a QueryDef on a INNER join
    public async Task EvaluatingQueryDefWithInnerJoin()
    {
      await ArcGIS.Desktop.Framework.Threading.Tasks.QueuedTask.Run(() =>
      {
        using (Geodatabase geodatabase = new Geodatabase(new DatabaseConnectionFile(new Uri("path\\to\\sde\\file"))))
        {
          QueryDef queryDef = new QueryDef()
          {
            Tables = "People INNER JOIN States ON People.FK_STATE_ID = States.OBJECTID",
            SubFields = "People.OBJECTID, People.First_Name, People.Last_Name, People.City, States.State_Name"
          };
    
          using (RowCursor cursor = geodatabase.Evaluate(queryDef))
          {
            while (cursor.MoveNext())
            {
              using (Row row = cursor.Current)
              {
                // Handle row
              }
            }
          }
        }
      });
    }
    Evaluating a QueryDef on a nested - INNER and OUTER join
    public async Task EvaluatingQueryDefWithNestedJoin()
    {
      await ArcGIS.Desktop.Framework.Threading.Tasks.QueuedTask.Run(() =>
      {
        using (Geodatabase geodatabase = new Geodatabase(
          new DatabaseConnectionFile(new Uri("path\\to\\sde\\file"))))
        {
          QueryDef queryDef = new QueryDef()
          {
            Tables = "((People INNER JOIN States ON People.FK_STATE_ID = States.OBJECTID) LEFT OUTER JOIN Homes ON People.OBJECTID = Homes.FK_People_ID)",
            SubFields = "People.OBJECTID, People.First_Name, People.Last_Name, States.State_Name, Homes.Address"
          };
    
          using (RowCursor cursor = geodatabase.Evaluate(queryDef, false))
          {
            while (cursor.MoveNext())
            {
              using (Row row = cursor.Current)
              {
                // Handle row
              }
            }
          }
        }
      });
    }
    Creating a QueryTable using a query which joins two versioned tables in a geodatabase
    public async Task QueryTableJoinWithVersionedData()
    {
      await ArcGIS.Desktop.Framework.Threading.Tasks.QueuedTask.Run(() =>
      {
        QueryDef queryDef = new QueryDef
        {
          Tables = "CommunityAddress JOIN MunicipalBoundary on CommunityAddress.Municipality = MunicipalBoundary.Name",
          SubFields = "CommunityAddress.OBJECTID, CommunityAddress.Shape, CommunityAddress.SITEADDID, CommunityAddress.ADDRNUM, CommunityAddress.FULLNAME, CommunityAddress.FULLADDR, CommunityAddress.MUNICIPALITY, MunicipalBoundary.Name, MunicipalBoundary.MUNITYP, MunicipalBoundary.LOCALFIPS",
        };
    
        using (Geodatabase testVersion1Geodatabase = new Geodatabase(new DatabaseConnectionProperties(EnterpriseDatabaseType.Oracle)
        {
          AuthenticationMode = AuthenticationMode.DBMS,
          Instance = "instance",
          User = "user",
          Password = "password",
          Database = "database",
          Version = "user.testVersion1"
        }))
        {
          QueryTableDescription queryTableDescription = new QueryTableDescription(queryDef)
          {
            Name = "CommunityAddrJounMunicipalBoundr",
            PrimaryKeys = testVersion1Geodatabase.GetSQLSyntax().QualifyColumnName("CommunityAddress", "OBJECTID")
          };
    
          // Will be based on testVersion1.
          using (Table queryTable = testVersion1Geodatabase.OpenQueryTable(queryTableDescription))
          {
            // Use queryTable.
          }
        }
    
        using (Geodatabase testVersion2Geodatabase = new Geodatabase(new DatabaseConnectionProperties(EnterpriseDatabaseType.Oracle)
        {
          AuthenticationMode = AuthenticationMode.DBMS,
          Instance = "instance",
          User = "user",
          Password = "password",
          Database = "database",
          Version = "user.testVersion2"
        }))
        {
          QueryTableDescription queryTableDescription = new QueryTableDescription(queryDef)
          {
            Name = "CommunityAddrJounMunicipalBoundr",
            PrimaryKeys = testVersion2Geodatabase.GetSQLSyntax().QualifyColumnName("CommunityAddress", "OBJECTID")
          };
    
          // Will be based on testVersion2.
          using (Table queryTable = testVersion2Geodatabase.OpenQueryTable(queryTableDescription))
          {
            // Use queryTable.
          }
        }
      });
    }
    Requirements

    Target Platforms: Windows 11, Windows 10, Windows 8.1

    See Also