在 ADO 中动态改变Access表中的字段的类型,将字符型字段的‘允许空字符串’ 设置为‘是’。缺省为‘否’在VB中可以这样 ADOX 可以。 Function ChengTableFieldPro_ADO()
Dim MyTableName As String
Dim MyFieldName As String
Dim GetFieldDesc_ADO
Dim GetFieldDescription
MyTableName = "ke_hu"
MyFieldName = "dw_name"
Dim MyDB As New ADOX.Catalog
Dim MyTable As ADOX.Table
Dim MyField As ADOX.Column
On Error GoTo Err_GetFieldDescription
MyDB.ActiveConnection = CurrentProject.Connection
Set MyTable = MyDB.Tables(MyTableName)
GetFieldDesc_ADO =
MyTable.Columns(MyFieldName).Properties("Description")
Dim pro As ADODB.Property
For Each pro In
MyTable.Columns(MyFieldName).Properties
Debug.Print pro.Name & " : " & pro.Value & "
---- type : " & pro.Type
Next
With MyTable.Columns(MyFieldName)
'.Properties("nullable") = True '必填
'必填无法用上述代码设置,出错提示为:
'多步 OLE DB 操作产生错误。如果可能,请检查每个 OLE DB 状态值。没有工作被完成。
'目前可以用以下语句设置:
'CurrentDb.TableDefs("ke_hu").Fields("DW_NAME").Properties("Required")
= False
.Properties("Jet OLEDB:Allow Zero Length") =
True '允许空
.Properties("default") = "默默默默认认认认" '默认值
End With
Set MyDB = Nothing
Bye_GetFieldDescription:
Exit Function
Err_GetFieldDescription:
Beep
Debug.Print Err.Description
MsgBox Err.Description, vbExclamation
GetFieldDescription = Null
Resume Bye_GetFieldDescription
End Function
Dim MyTableName As String
Dim MyFieldName As String
Dim GetFieldDesc_ADO
Dim GetFieldDescription
MyTableName = "ke_hu"
MyFieldName = "dw_name"
Dim MyDB As New ADOX.Catalog
Dim MyTable As ADOX.Table
Dim MyField As ADOX.Column
On Error GoTo Err_GetFieldDescription
MyDB.ActiveConnection = CurrentProject.Connection
Set MyTable = MyDB.Tables(MyTableName)
GetFieldDesc_ADO =
MyTable.Columns(MyFieldName).Properties("Description")
Dim pro As ADODB.Property
For Each pro In
MyTable.Columns(MyFieldName).Properties
Debug.Print pro.Name & " : " & pro.Value & "
---- type : " & pro.Type
Next
With MyTable.Columns(MyFieldName)
'.Properties("nullable") = True '必填
'必填无法用上述代码设置,出错提示为:
'多步 OLE DB 操作产生错误。如果可能,请检查每个 OLE DB 状态值。没有工作被完成。
'目前可以用以下语句设置:
'CurrentDb.TableDefs("ke_hu").Fields("DW_NAME").Properties("Required")
= False
.Properties("Jet OLEDB:Allow Zero Length") =
True '允许空
.Properties("default") = "默默默默认认认认" '默认值
End With
Set MyDB = Nothing
Bye_GetFieldDescription:
Exit Function
Err_GetFieldDescription:
Beep
Debug.Print Err.Description
MsgBox Err.Description, vbExclamation
GetFieldDescription = Null
Resume Bye_GetFieldDescription
End Function
TABLE_NAME:表名
COLUMN_NAME:字段名
datatype:数据类型(此处应使用原来的数据类型)
可通过TADOQuery的ExecSQL执行。
增加一个字段,但是我要增加的这个字段 允许空字符串 NOT NULL 为不允许为空(不允许等于NULL) 允许空字符串为可以为“”;
例 : 增加一个字段为‘内容’,varchar(50) not null 允许空字符串