Fields.Delete 方法 (DAO)

适用于：Access 2013、Office 2013

从 Fields 集合中删除 Field 。

语法

表达式 。删除 (名称)

表达式 表示 Fields 对象的变量。

参数

名称	必需/可选	数据类型	说明
Name	必需	字符串	要删除的字段。

备注

删除已存储的对象会立即发生，但是，对于受数据库结构更改影响的其他任何集合，应使用 Refresh 方法。

示例

此示例使用 Append 方法或 Delete 方法来修改 TableDef 的 Fields 集合。 要使该过程运行，需要 AppendDeleteField 过程。

    Sub AppendX() 
     
     Dim dbsNorthwind As Database 
     Dim tdfEmployees As TableDef 
     Dim fldLoop As Field 
     
     Set dbsNorthwind = OpenDatabase("Northwind.mdb") 
     Set tdfEmployees = dbsNorthwind.TableDefs!Employees 
     
     ' Add three new fields. 
     AppendDeleteField tdfEmployees, "APPEND", _ 
     "E-mail", dbText, 50 
     AppendDeleteField tdfEmployees, "APPEND", _ 
     "Http", dbText, 80 
     AppendDeleteField tdfEmployees, "APPEND", _ 
     "Quota", dbInteger, 5 
     
     Debug.Print "Fields after Append" 
     Debug.Print , "Type", "Size", "Name" 
     
     ' Enumerate the Fields collection to show the new fields. 
     For Each fldLoop In tdfEmployees.Fields 
     Debug.Print , fldLoop.Type, fldLoop.Size, fldLoop.Name 
     Next fldLoop 
     
     ' Delete the newly added fields. 
     AppendDeleteField tdfEmployees, "DELETE", "E-mail" 
     AppendDeleteField tdfEmployees, "DELETE", "Http" 
     AppendDeleteField tdfEmployees, "DELETE", "Quota" 
     
     Debug.Print "Fields after Delete" 
     Debug.Print , "Type", "Size", "Name" 
     
     ' Enumerate the Fields collection to show that the new 
     ' fields have been deleted. 
     For Each fldLoop In tdfEmployees.Fields 
     Debug.Print , fldLoop.Type, fldLoop.Size, fldLoop.Name 
     Next fldLoop 
     
     dbsNorthwind.Close 
     
    End Sub 
     
    Sub AppendDeleteField(tdfTemp As TableDef, _ 
     strCommand As String, strName As String, _ 
     Optional varType, Optional varSize) 
     
     With tdfTemp 
     
     ' Check first to see if the TableDef object is 
     ' updatable. If it isn't, control is passed back to 
     ' the calling procedure. 
     If .Updatable = False Then 
     MsgBox "TableDef not Updatable! " & _ 
     "Unable to complete task." 
     Exit Sub 
     End If 
     
     ' Depending on the passed data, append or delete a 
     ' field to the Fields collection of the specified 
     ' TableDef object. 
     If strCommand = "APPEND" Then 
     .Fields.Append .CreateField(strName, _ 
     varType, varSize) 
     Else 
     If strCommand = "DELETE" Then .Fields.Delete _ 
     strName 
     End If 
     
     End With 
     
    End Sub