dbfunc.vb

代码：是由本人自主开发完成的

'[引入命名空间]
Imports System
Imports System.Data
Imports System.Drawing
Imports System.Data.OleDb
Module DBFunc


    '访问数据库公共变量
    Public StartPath As String = Application.StartupPath & "\大学语文考试系统数据库.mdb"
    Public ConnStr As String = "provider=microsoft.jet.oledb.4.0;"
    Public ConnectStr As String = ConnStr & "data source=" & StartPath
    Public DataAdapter As OleDbDataAdapter
    Public DataConnection As OleDbConnection
    Public MyDataset As DataSet

    '访问数据库函数，成功，则返回查询数据
    Public Function GetDataFromDB(ByVal sqlstr As String) As DataSet
        Try
            DataConnection = New OleDbConnection
            DataConnection.ConnectionString = ConnectStr
            DataAdapter = New OleDbDataAdapter(sqlstr, DataConnection)
            MyDataset = New DataSet
            MyDataset.Clear()
            DataAdapter.Fill(MyDataset)
            DataConnection.Close()
        Catch ex As Exception
            MsgBox(Err.Description)
        End Try
        If MyDataset.Tables(0).Rows.Count > 0 Then
            Return MyDataset
        Else
            Return Nothing
        End If
    End Function

    '定义一个返回执行数据操作成功标志的。用于实现对数据的删除，修改，添加
    Public Function UpdateDataBase(ByVal sqlstr As String) As Boolean
        Dim sqlconn As New OleDbConnection(ConnectStr)
        Try
            Dim cmdtable As OleDbCommand = New OleDbCommand(sqlstr, sqlconn)
            cmdtable.CommandType = CommandType.Text
            sqlconn.Open()
            cmdtable.ExecuteNonQuery()
            sqlconn.Close()
        Catch ex As Exception
            MessageBox.Show(Err.Description)
            Return False
        End Try
        Return True
    End Function
    
End Module