Microsoft KB Archive/112107

= ACC2: How to Index an Existing Field with DAO =

Article ID: 112107

Article Last Modified on 11/6/2000

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APPLIES TO


 * Microsoft Access 2.0 Standard Edition

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This article was previously published under Q112107



SUMMARY
Advanced: Requires expert coding, interoperability, and multiuser skills.

This article demonstrates how to create a compound (multiple- field) index in an existing table using data access objects (DAO).

This article assumes that you are familiar with Access Basic and with creating Microsoft Access applications using the programming tools provided with Microsoft Access. For more information on Access Basic, please refer to the "Building Applications" manual, Chapter 3, "Introducing Access Basic."



MORE INFORMATION
An Index object contains the fields that are being indexed, and usually contains only a single field. The Index object created in the example below will have two fields appended to it, creating a multiple- field index.

The example below demonstrates how to create a multiple- field index with DAO:

 Open the sample database NWIND.MDB.  Create the following new table:

   Table: Interviews --   Field Name: CustomerID Data Type: Number Field Size: Long Integer Field Name: InterviewerID Data Type: Number Field Size: Long Integer Field Name: Appointment Data Type: Date/Time  Save the table as Interviews without creating a primary key, and then close it. Create a new module and type the following line in the Declarations section:

Option Explicit   Type the following function in the module:

      '--- 'PURPOSE: Adds a multiple-field index to a table. 'ACCEPTS: Nothing. 'RETURNS: Nothing. '---      Function AddMultiIndex Dim DB As Database, TDef As TableDef Dim Idx As Index, Fld As Field

Set DB = DBEngine.Workspaces(0).Databases(0)

' Open the table definition. Set TDef = DB.TableDefs("Interviews")

' Create an index called PrimaryKey for this TableDef ' .. and turn on the Primary and Required properties. Set Idx = TDef.CreateIndex("PrimaryKey") Idx.Primary = True Idx.Required = True Idx.Ignorenulls = False

' Create an index field with the same name as a table field, ' .. then append it to the index. Set Fld = Idx.CreateField("CustomerID") Idx.fields.Append Fld

'  Do the second field the same way. Set Fld = Idx.CreateField("InterviewerID") Fld.Attributes = DB_DESCENDING Idx.fields.Append Fld

'  Append the index to the TableDef. TDef.indexes.Append Idx

End Function  Save the module as DAOaddMultiIndex.</li> From the View menu, choose Immediate Window.</li> Type the following in the Immediate window, and then press ENTER:

? AddMultiIndex </li> Close the Immediate window and the module, and then open the Interviews table in Design view. Note the compound primary key on the CustomerID and InterviewerID fields.</li></ol>

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