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TableDef.CreateField Method (DAO)
16.03.2019
23:43
Текстовые метки: VBA_Acces, CreateField, DAO
Раздел: !Закладки - VBA - Access

TableDef.CreateField Method (DAO)



Office 2013 and later





Other Versions








Last modified: March 09, 2015


Applies to: Access 2013 | Office 2013


In this article

Syntax

Remarks

Example

About the Contributors



Creates a new Field object (Microsoft Access workspaces only).



Syntax




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expression .CreateField(Name, Type, Size)


expression A variable that represents a TableDef object.


Parameters







Name


Required/Optional


Data Type


Description


Name

Optional

Variant

A String that uniquely names the new Field object. See the Name property for details on valid Field names.


Type

Optional

Variant

A constant that determines the data type of the new Field object. See the Type property for valid data types.


Size

Optional

Variant

An Integer that indicates the maximum size, in bytes, of a Field object that contains text. See the Size property for valid size values. This argument is ignored for numeric and fixed-width fields.


Return Value



Field



Remarks




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You can use the CreateField method to create a new field, as well as specify the name, data type, and size of the field. If you omit one or more of the optional parts when you use CreateField, you can use an appropriate assignment statement to set or reset the corresponding property before you append the new object to a collection. After you append the new object, you can alter some but not all of its property settings. See the individual property topics for more details.


The type and Size arguments apply only to Field objects in a TableDef object. These arguments are ignored when a Field object is associated with an Index or Relation object.


If Name refers to an object that is already a member of the collection, a run-time error occurs when you use the Append method.


To remove a Field object from a Fields collection, use the Delete method on the collection. You can't delete a Field object from a TableDef object's Fields collection after you create an index that references the field.


Link provided by: Community Member Icon The UtterAccess community | About the Contributors


• Adding a hyperlink field to an existing table with DAO




Example




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The following example shows how to create a calculated field. The CreateField method creates a field named FullName. The Expression property is then set to the expression that calculates the value of the field.


Sample code provided by: The Microsoft Access 2010 Programmer’s Reference | About the Contributors




VBA





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Sub CreateCalculatedField()

Dim dbs As DAO.Database

Dim tdf As DAO.TableDef

Dim fld As DAO.Field2

' get the database

Set dbs = CurrentDb()

' create the table

Set tdf = dbs.CreateTableDef("tblContactsCalcField")

' create the fields: first name, last name

tdf.Fields.Append tdf.CreateField("FirstName", dbText, 20)

tdf.Fields.Append tdf.CreateField("LastName", dbText, 20)

' create the calculated field: full name

Set fld = tdf.CreateField("FullName", dbText, 50)

fld.Expression = "[FirstName] & "" "" & [LastName]"

tdf.Fields.Append fld

' append the table and cleanup

dbs.TableDefs.Append tdf

Cleanup:

Set fld = Nothing

Set tdf = Nothing

Set dbs = Nothing

End Sub




About the Contributors



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