public class XCField : XField

Public Class XCField
	Inherits XField

Imports System
Imports BioloMICS.BioCallback
Imports BioloMICS.SharedClasses

Public Class Program

    <STAThread()>
    Shared Sub Main()

        Dim program As New Program
        program.ChangeField()
    End Sub

    '    Write sub functions here
    Public Sub ChangeField()
        '    get the current connection
        Dim SqlCo As XConnection = Run.GetCurrentConnection()
        If SqlCo Is Nothing Then
            Return
        End If

        '    get a table from its User name
        Dim TableDef As XTableDef = SqlCo.GetTableDefByUserNameEng("Your_Table_Name")
        If TableDef Is Nothing Then   '    may happen if that table doesn't exist
            Return
        End If
        '    load a C-Field from that table
        Dim FieldDefMap As New XFieldDefMap
        Dim FieldDef As XFieldDef = SqlCo.GetFieldByUserNameEng("Your_C_Field_name", TableDef.Key)
        If FieldDef Is Nothing Then   '    that field doesn't exist
            Return
        End If
        FieldDefMap.Add(FieldDef)

        '    load all records
        Dim Where As XWhere = XWhere.All

        Dim RecordMap As XRecordMap = Run.LoadRecords(TableDef.Key, FieldDefMap, Where)
        If RecordMap.Count() = 0 Then
            Return   '    no record loaded: nothing else to do
        End If
        For Each Record As XRecord In RecordMap
            '    get the Field from the loaded record
            Dim Field As XCField = TryCast(Record.Fields(FieldDef.Key), XCField)
            If Field Is Nothing Then   '    this field doesn't exist or is not a C-Field
                Continue For
            End If
            '    *****    C Field    meaning *****
            '    Display          Value            Meaning
            '    ?                0            Unknown
            '    variable        1            Character is variable
            '    yes            2            Character is present
            '    no                3            Character is absent

            '    change the field value: replace '?' by 'variable' for the first subfield
            If Field.Subfield(0) = 0 Then    '    ?
                Field.Subfield(0) = 1         '    = variable
            End If

            Record.Save(False)
        Next
    End Sub
End Class