学习记录：VB.NET.操作ACCESS数据库
从98年到现在，VB6使用了20多年，真的舍不得扔掉，但是随着新计算机预装操作系统的版本越来越高，做好的安装包在安装时遇到的问题越来越多，无奈之下只能转向使用VB.NET了。安装了VS2005来学习,这个家伙不错，个头不是特大，在xp上跑的很顺畅，哈哈。
今天学习在VB.NET上操作ACCESS数据库，为防止将来忘记，记录于此。
一、清空某张表中的全部数据
Dim cn As OleDbConnection
cn = New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & Application.StartupPath & "\Comm.mdb")
cn.Open() '打开当前文件夹下comm.mdb文件
Dim cmd As New OleDbCommand()
cmd.Connection = cn
cmd.CommandText = "delete * from tbTest" '清空表tbTest
cmd.ExecuteNonQuery()
cmd.Dispose() '释放资源
cn.Close()
cn.Dispose() '释放资源 感觉很像VB6里的 set xx=nothing
MessageBox.Show("全部删除完成")
二 向某张表插入数据
Dim cn As OleDbConnection
cn = New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & Application.StartupPath & "\Comm.mdb")
cn.Open() '打开当前文件夹下comm.mdb文件
Dim cmd As New OleDbCommand()
cmd.Connection = cn
Dim id As Long
Dim sex As String
Dim address As String
id = 1
sex = "男"
address = "松山区"
cmd.CommandText = "insert into tbtest (id,sex,address) values(" & id & "," & Chr(39) & sex & Chr(39) & "," & Chr(39) & address & Chr(39) & ")"
cmd.ExecuteNonQuery()
id = 2
sex = "男"
address = "红山区"
cmd.CommandText = "insert into tbtest (id,sex,address) values(" & id & "," & Chr(39) & sex & Chr(39) & "," & Chr(39) & address & Chr(39) & ")"
cmd.ExecuteNonQuery()
id = 3
sex = "女"
address = "元宝山区"
cmd.CommandText = "insert into tbtest (id,sex,address) values(" & id & "," & Chr(39) & sex & Chr(39) & "," & Chr(39) & address & Chr(39) & ")"
cmd.ExecuteNonQuery()
cmd.Dispose()
cn.Close()
cn.Dispose()
MessageBox.Show("插入3行测试完成")
三 修改
Dim cn As OleDbConnection
cn = New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & Application.StartupPath & "\Comm.mdb")
cn.Open() '打开当前文件夹下comm.mdb文件
Dim cmd As New OleDbCommand()
cmd.Connection = cn
Dim strNewAddress As String
strNewAddress = "平庄"
Dim strCondition As String
strCondition = "元宝山区"
cmd.CommandText = "update tbtest set address=" & Chr(39) & strNewAddress & Chr(39) & " where address=" & Chr(39) & strCondition & Chr(39)
cmd.ExecuteNonQuery()
cmd.Dispose()
cn.Close()
cn.Dispose()
MessageBox.Show("修改测试完成")
四 删除
Dim cn As OleDbConnection
cn = New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & Application.StartupPath & "\Comm.mdb")
cn.Open() '打开当前文件夹下comm.mdb文件
Dim cmd As New OleDbCommand()
cmd.Connection = cn
Dim strCondition As String
strCondition = "平庄"
cmd.CommandText = "delete from tbtest where address=" & Chr(39) & strCondition & Chr(39)
cmd.ExecuteNonQuery()
cmd.Dispose()
cn.Close()
cn.Dispose()
MessageBox.Show("删除测试完成")
五 查询
Dim cn As OleDbConnection
cn = New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & Application.StartupPath & "\Comm.mdb")
cn.Open() '打开当前文件夹下comm.mdb文件
Dim lngIDCondition As Long
lngIDCondition = 2
Dim strSexCondition As String
strSexCondition = "男"
Dim cmd As New OleDbCommand()
cmd.Connection = cn
cmd.CommandText = "select * from tbTest where id=" & lngIDCondition & " and sex=" & Chr(39) & strSexCondition & Chr(39)
Dim dr As OleDbDataReader
dr = cmd.ExecuteReader()
If dr.HasRows() = True Then
Do While dr.Read() = True '如果有记录，就循环打印符合条件的记录的address字段中内容
Debug.Print(dr.Item("id") & " " & dr.Item("sex") & " " & dr.Item("Address"))
Loop
Else
MessageBox.Show("搜索失败")
End If
dr.Close()
'结果为
'2 男 红山区
'查询全部
cmd.CommandText = "select * from tbTest order by id"
dr = cmd.ExecuteReader()
If dr.HasRows() = True Then
Do While dr.Read() = True '如果有记录，就循环打印符合条件的记录的address字段中内容
Debug.Print(dr.Item("id") & " " & dr.Item("sex") & " " & dr.Item("Address"))
Loop
End If
'结果为
'1 男 松山区
'2 男 红山区
dr.Close()
cmd.Dispose()
cn.Close()
cn.Dispose()
六 总结
练习后发现，除了查询，VB.NET操作ACCESS数据库的方法与VB6使用差不多，仅仅变量类型不一样。
但是查询要麻烦些。