LinkData method

Article
11/16/2006

Links data as a DataSet object; similar to the Link Data Wizard. Linked sets can be updated when the source data has changed.

Applies to

Collections: DataSets

Syntax

Click a parameter to jump to its description below.

object .LinkData(DataSourceMoniker, PrimaryKeyField, [ArrayOfFields], [Country], [Delimiter], [ImportFlags])

Parameters

Part Description

object Required. An expression that returns a DataSets collection.

DataSourceMoniker Required String. File name to link to. Can also provide information on which part of the file to link to. See the DataSourceMoniker syntax topic for the correct syntax to use for this parameter.

PrimaryKeyField Required Variant. Key field in the data file. Can be either the field name or the ordinal. Is always linked to, whether it is listed in ArrayOfFields or not. Must be a unique field of values (for example, customer number or order number).

ArrayOfFields

Optional Variant. A two-column array:

The first column contains the field name or an integer representing the field index (which starts at 1) of each field to link. If a Field object is not listed in the array, then it is given a GeographicFieldType property of geoFieldSkipped (except for the PrimaryKeyField, which is always linked).

The second column designates one of three ways to treat the record:

Use a GeoFieldType value, which MapPoint will geocode (see GeoFieldType values for a list of values and their descriptions).

Use a string, which MapPoint will interpret as the field name for geoFieldData.

Leave blank to have MapPoint determine the field's contents and title.

If this parameter is not supplied, then all fields in the data source are linked.

Country Optional GeoCountry. Country associated with the data. Default is geoCountryDefault. See the GeoCountry values topic for a list of GeoCountry values and their descriptions.

Delimiter

Optional GeoDelimiter. Characters that separate individual fields. Can be one or more characters. Required for linking to text files. Default is geoDelimiterDefault.

GeoDelimiter

Value

Description

geoDelimiterComma

Fields separated by commas (","). Default for .csv files.

geoDelimiterDefault

MapPoint determines the delimiter based on the file type.

File type	Default Delimiter
.asc	tab
.csv	comma
.tab	tab
.txt	tab

geoDelimiterSemicolon

Fields separated by semicolons.

geoDelimiterTab

Fields separated by tabs ("\t"). Default for .tab, .txt, and .asc files.

ImportFlags

Optional Long. Provides information about the DataSourceMoniker and the data in the file. Multiple values can be passed by using the Visual Basic "Or" operator (for example, geoImportExcelNamedRange Or geoImportFirstRowIsNotHeadings).

GeoImportFlags	Value	Description
geoImportAccessQuery	4	DataSourceMoniker specifies an Access query.
geoImportAccessTable	0	DataSourceMoniker specifies an Access table. Default.
geoImportExcelA1	0	DataSourceMoniker specifies Excel A1 syntax. Default.
geoImportExcelNamedRange	4	DataSourceMoniker specifies an Excel named range.
geoImportExcelR1C1	2	DataSourceMoniker specifies Excel R1C1 syntax.
geoImportExcelSheet	0	DataSourceMoniker specifies an Excel worksheet. Default.
geoImportFirstRowIsHeadings	0	First row of the file contains field names. Default.
geoImportFirstRowNotHeadings	1	First row of the file does not contain field names.

Remarks

To open the Link Data Wizard for user input, use the ShowLinkWizard method on the DataSets collection.

To learn more about mapping data, see the Getting started with data sets and data mapping reference topic.

Example

  
    Sub LinkToMultipleSources()


  Dim objApp As New MapPoint.Application
  objApp.Visible = True
  objApp.UserControl = True
  Dim szconn As String
  Dim oDS As MapPoint.DataSet


  With objApp.ActiveMap.DataSets
    'Text file with tab
    szconn = objApp.Path & "\Samples\Sales.txt"
    Set oDS = .LinkData(szconn, "ID", , geoCountryUnitedStates, geoDelimiterTab)


    'CSV text file
    szconn = objApp.Path & "\Samples\Sales.csv"
    Set oDS = .LinkData(szconn,"ID", , geoCountryUnitedStates, geoDelimiterComma)


    'Access database with a table
    szconn = objApp.Path & "\Samples\Clients.mdb!Addressestable"
    Set oDS = .LinkData(szconn,"ID",  , geoCountryUnitedStates, , geoImportAccessTable)


    'Access database with a query
    szconn = objApp.Path & "\Samples\Clients.mdb!AddressQuery"
    Set oDS = .LinkData(szconn,"ID",  , geoCountryUnitedStates, , geoImportAccessQuery)


    'Excel sheet
    szconn = objApp.Path & "\Samples\Sales.xls!Sheet1!A1:D3"
    Set oDS = .LinkData(szconn,"ID",  , geoCountryUnitedStates, , geoImportExcelA1)


    'Excel sheet R1C1 reference
    szconn = objApp.Path & "\Samples\Sales.xls!Sheet1!R1C1:R3C9"
    Set oDS = .LinkData(szconn,"ID",  , geoCountryUnitedStates, , geoImportExcelR1C1)


    'Excel sheet named range
    szconn = objApp.Path & "\Samples\SampData.xls!First10Clients"
    Set oDS = .LinkData(szconn,"F1",  , geoCountryUnitedStates, , geoImportExcelNamedRange)
  End With


End Sub

Note This sample code is specific for use in MapPoint North America; it is for illustration purposes only.

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