主要代码如下：1、登录界面代码：Dim cn As New ADODB。ConnectionDim rst As New ADODB。RecordsetPrivate Sub Command1_Click（) Set cn = New ADODB。Connection Set rst = New ADODB。Recordset Static i% cn。ConnectionString = "Provider=SQLOLEDB。1；Persist Security Info=False；User ID=sa；Initial Catalog=students info;Data Source=C1847” cn.Open usna = Trim（Text1。Text) mysql = ”select ＊ from 用户表 where 用户名=’" ＆ usna & ”’” rst。Open mysql, cn If rst。EOF Then MsgBox ”用户名不存在！” cn。Close Text1.Text = "” Text2.Text = ”” Text1。SetFocus Else If Trim(rst（"密码”）) = Trim（Text2.Text) Then 管理界面.Show Else i = i + 1 If i < 3 Then MsgBox ”用户名或密码错误！”, vbOKOnly + vbExclamation， "警告” cn。Close Text2。Text = ”” Text1。Text = "” Text1。SetFocus Else MsgBox ”该用户已被锁定！", vbOKOnly + vbExclamation, "警告" End If End If End If End SubPrivate Sub Command2_Click（)Text1。Text = ””Text2。Text = "”Text3。Text = "”End Sub2、管理界面代码:Private Sub Sinsert_Click(）添加学生信息。ShowEnd SubPrivate Sub Sselect_Click()查询学生信息.ShowEnd SubPrivate Sub sustu_Click（）查询更新学生信息.ShowEnd SubPrivate Sub xgmm_Click（）修改密码。ShowEnd SubPrivate Sub yhzc_Click（）用户注册.ShowEnd Sub3、查询学生信息代码：Dim cn As New ADODB。ConnectionDim rst As New ADODB。RecordsetPrivate Sub Command1_Click（) Set cn = New ADODB.Connection Set rst = New ADODB。Recordset cn。ConnectionString = ”Provider=SQLOLEDB.1；Persist Security Info=False；User ID=sa;Initial Catalog=students info；Data Source=C1847" cn。Open If Combo1。Text <〉 "” Then mysql = ”select ＊ from 学生信息表 where 系别=’” ＆ Trim（Combo1。Text） ＆ ”'” rst.Open mysql， cn If rst.EOF Then MsgBox ”没有学生！", vbOKOnly + vbExclamation, ”警告" Combo1。Text = "” Else With MSFlexGrid1...
