通用
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连接数据库(拼接连接数据库字符串,调用函数即可):
Dim Con As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source= ATM.mdb" Dim connConnection As OleDb.OleDbConnection = New OleDb.OleDbConnection connConnection.ConnectionString = Con connConnection.Open()
验证用户名密码(就是拿着界面上输入的用户名密码 去数据库里面匹配,如果可以找到就通过):
Private Function UserIsValid() As Boolean '连接数据库 Dim Con As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source= ATM.mdb" Dim connConnection As OleDb.OleDbConnection = New OleDb.OleDbConnection connConnection.ConnectionString = Con connConnection.Open()
'验证一下用户名密码是否存在 Dim strsql As String = "select * from AccountInfo where AccountNo = '" & _ Trim(TextBox1.Text) & "' and Password = '" & Trim(TextBox2.Text) & "'" Dim connCommand As OleDb.OleDbCommand = New OleDb.OleDbCommand(strsql,connConnection) Dim myReader As OleDb.OleDbDataReader = connCommand.ExecuteReader '如果有数据 If myReader.HasRows Then myReader.Read() '读一行数据到reader里面 If Trim(TextBox1.Text) = myReader(1) And Trim(TextBox2.Text) = myReader(2) Then connConnection.Close() Return True Else connConnection.Close() Return False End If End If connConnection.Close() '没数据直接返回错误 Return False End Function
退出(其实就是把所有打开的窗口都隐藏,把登陆窗口显示就可以了):
For Each f As Form In Application.OpenForms f.Hide() frmLogin.Show() Next
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客户
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取款:
'连接数据库 Dim Con As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source= ATM.mdb" Dim connConnection As OleDb.OleDbConnection = New OleDb.OleDbConnection connConnection.ConnectionString = Con connConnection.Open() '修改金额(存钱) Dim sql As String = "update AccountInfo set Balance = Balance + " + TextBox1.Text + " where AccountNo = '" + frmLogin.TextBox1.Text + "'" Dim cmd As OleDb.OleDbCommand = New OleDb.OleDbCommand(sql,connConnection) cmd.ExecuteNonQuery() '记录操作日志 sql = "insert into AccountAct (AccountNo,Lastopt,Amount) values ('" & Trim(frmLogin.TextBox1.Text) & "','" & Trim(DateTime.Now.ToString()) & "'," & CType(TextBox1.Text,Double) & ")" Dim cmd2 As OleDb.OleDbCommand = New OleDb.OleDbCommand(sql,connConnection) cmd2.ExecuteNonQuery() connConnection.Close()
存款:
'连接数据库 Dim Con As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source= ATM.mdb" Dim connConnection As OleDb.OleDbConnection = New OleDb.OleDbConnection connConnection.ConnectionString = Con connConnection.Open() '修改金额(取钱) Dim sql As String = "update AccountInfo set Balance = Balance - " + TextBox2.Text + " where AccountNo = '" + frmLogin.TextBox1.Text + "'" Dim cmd As OleDb.OleDbCommand = New OleDb.OleDbCommand(sql,connConnection) cmd.ExecuteNonQuery() '记录操作日志 sql = "insert into AccountAct (AccountNo,Integer) & ")" cmd = New OleDb.OleDbCommand(sql,connConnection) cmd.ExecuteNonQuery() connConnection.Close()
查询账户:
'连接数据库 Dim Con As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source= ATM.mdb" Dim connConnection As OleDb.OleDbConnection = New OleDb.OleDbConnection connConnection.ConnectionString = Con connConnection.Open() Dim sql As String = "select Balance from AccountInfo where AccountNo = '" + frmLogin.TextBox1.Text + "'" Dim cmd As OleDb.OleDbCommand = New OleDb.OleDbCommand(sql,connConnection) Dim myReader As OleDb.OleDbDataReader = cmd.ExecuteReader If myReader.HasRows Then myReader.Read() Label1.Text = myReader(0) Else MessageBox.Show("未找到账户信息") End If connConnection.Close()
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管理员
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记录操作日志:
sql = "insert into AccountAct (AccountNo,connConnection) cmd.ExecuteNonQuery() connConnection.Close()
查看所有操作日志:
'连接数据库 Dim Con As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source= ATM.mdb" Dim connConnection As OleDb.OleDbConnection = New OleDb.OleDbConnection connConnection.ConnectionString = Con connConnection.Open() '把查询的数据取出来放到data set Dim strsql As String = "select * from AccountAct" Dim myDataSet As DataSet = New DataSet() Dim myAdapter As OleDb.OleDbDataAdapter = New OleDb.OleDbDataAdapter(strsql,connConnection) myAdapter.Fill(myDataSet,"AccountAct") connConnection.Close() '把数据从dataset中取出来显示在控件上() DataGridView1.DataSource = myDataSet.Tables(0) DataGridView1.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.AllCells
查看所有用户账号
'连接数据库 Dim Con As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source= ATM.mdb" Dim connConnection As OleDb.OleDbConnection = New OleDb.OleDbConnection connConnection.ConnectionString = Con connConnection.Open() '把查询的数据取出来放到data set Dim strsql As String = "select * from AccountInfo" Dim myDataSet As DataSet = New DataSet() Dim myAdapter As OleDb.OleDbDataAdapter = New OleDb.OleDbDataAdapter(strsql,"AccountInfo") connConnection.Close() '把数据从dataset中取出来显示在控件上() DataGridView1.DataSource = myDataSet.Tables(0) DataGridView1.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.AllCells