如何修复此代码以将所有属性带入访问数据库？ [英] How to fix this code to bring all properties in access database ?

问题描述

 Public Sub ShowFieldsAccess(dgv As DataGridView, table As DevExpress.XtraEditors.CheckedListBoxControl, txtmasar As DevExpress.XtraEditors.TextEdit, txtpk As TextBox)
 

            dgv.DataSource = Nothing
        dgv.Rows.Clear()
        Dim NameTable As String = table.Text
        For Each Dr In mytb.Rows
            Dim cmd As OleDbCommand = cn.CreateCommand
            cmd.CommandText = String.Format("Select * From [{0}]", NameTable)
                Dim reader As OleDbDataReader = cmd.ExecuteReader(CommandBehavior.KeyInfo)
                x = reader.GetSchemaTable
        Next
            For Each item As DataRow In x.Rows
                                Dim n As Integer = dgv.Rows.Add(item)
                              dgv.Rows(n).Cells(1).Value = item(0).ToString
                dgv.Rows(n).Cells(2).Value = GetTypeAccessGET(item(5).ToString.Replace("System.", ""))

                If item(8).ToString() = "True" Then : dgv.Rows(n).Cells(0).Value = "False"
                Else : dgv.Rows(n).Cells(0).Value = "True" : End If
                n += 1
                '-----------------
                Dim con As New ADODB.Connection
                con.Open(cn.ConnectionString)
                Dim MyDB As New ADOX.Catalog
                MyDB.ActiveConnection = con
                Dim MyTable As ADOX.Table = MyDB.Tables(NameTable)
                Dim Desc As String = item(0).ToString
                dgv.Rows(n - 1).Cells(3).Value = MyTable.Columns(Desc).Properties("Description").Value
            Next item
            '--------------------------------------------------------------------------------------------------------------------S
            Dim dt As New DataTable With {.TableName = String.Concat("Schema_", NameTable)}
            Dim db As AccessDao.Database
            Dim TheTableDef As AccessDao.TableDef
            Dim Engine As New AccessDao.DBEngine()
            db = Engine.OpenDatabase(txtmasar.Text.ToString)
            TheTableDef = db.TableDefs(NameTable)
            With TheTableDef
                For Each f As AccessDao.Field In .Fields
                    Dim d As AccessDao.DataTypeEnum
                    Dim FieldType = CType(
                        System.ComponentModel.TypeDescriptor _
                            .GetConverter(d) _
                            .ConvertFromString(f.Type.ToString), 
                            AccessDao.DataTypeEnum)

                           For Each item1 As DataRow In x.Rows

                        Dim v As Integer = dgv.Rows.Count - 1
                        dgv.Rows(v).Cells(4).Value = f.Required
                        dgv.Rows(v).Cells(5).Value = f.Size
                        dgv.Rows(v).Cells(6).Value = f.AllowZeroLength
                        '  v += 1
                    Next item1
                Next f


            End With
            Return
end sub

我有什么尝试过：



我厌倦了这段代码，我试图将Access数据库中表字段的所有属性带到DataGridView

请帮我发现代码中的错误



非常感谢



https://image.ibb.co/byDdVQ/Capture.png [ ^ ]

推荐答案

获取在表（或任何结果集）的定义中，我使用DataReader的GetSchemaTable方法。

OleDbDataReader.GetSchemaTable Method（System.Data.OleDb） [ ^ ]

To get the definition of a table (or any result set), I use the GetSchemaTable method of a DataReader.
OleDbDataReader.GetSchemaTable Method (System.Data.OleDb)[^]

System.Data.DataTable result = null ;

using
(
    System.Data.IDataReader dr
=
    this.ExecuteReader 
    ( 
        System.Data.CommandBehavior.SchemaOnly 
        |
        System.Data.CommandBehavior.KeyInfo 
    , 
        cmd 
    )
)
{
    schema = dr.GetSchemaTable() ;

    dr.Close() ;
}

返回的DataTable的每一行都描述了SQL语句结果的一列。

对于OleDb提供程序，ProviderType是System.Data.OleDb.OleDbType中的值

OleDbType枚举（System.Data.OleDb） [ ^ ]



我将不得不研究为什么它似乎没有为Access中的列提供那些高级属性。

可能你需要

OleDbConnection.GetOleDbSchemaTable Method（Guid，Object []）（ System.Data.OleDb） [ ^ ]

但我还没有调查过。

Each row of the returned DataTable describes one column of the SQL statement result.
For an OleDb provider, the ProviderType is a value from System.Data.OleDb.OleDbType
OleDbType Enumeration (System.Data.OleDb)[^]

I'll have to look into why it doesn't appear to have those advanced properties for columns in Access.
It may be that you need
OleDbConnection.GetOleDbSchemaTable Method (Guid, Object[]) (System.Data.OleDb)[^]
but I haven't investigated it yet.

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