2.DOTNET零碎总结---VB.NET
修改数据存在多个txt
Box时,
sql语句的操作 1. 一个Button1的text为
查询和一个DataGridView1,点击
查询按钮的
代码 Private Sub Button1_Click(ByVal sender As System.Object,ByVal e As System.EventArgs) Handles Button1.Click Dim strConn = "Data Source=192.168.1.110/orcl;User ID=test;Password=orcl" Dim dbcmd As OracleCommand Dim dt = New DataTable("ds") Dim dbConnection As OracleConnection Try dbConnection = New OracleConnection(strConn) dbConnection.Open() dbcmd = dbConnection.CreateCommand dbcmd.CommandText = "select * from student" Dim da As OracleDataAdapter = New OracleDataAdapter(dbcmd) da.Fill(dt) DataGridView1.DataSource = dt '这时候可以把dt的值直接赋值给DataGridview1控件 Catch ex As Exception Msg
Box("
查询数据库出错") End Try End Sub 2.存在两个Text
Box1.Text
Box2,文本框和一个按钮,Button2,按钮text为
修改,点击后的
代码 Private Sub Button2_Click(ByVal sender As System.Object,ByVal e As System.EventArgs) Handles Button2.Click Dim username,password As String Dim temp,temp3 As String If Len(Text
Box1.Text.Trim) <> 0 Then username = "sname=" + "'" + Text
Box1.Text.Trim + "'" + "," Else username = "" End If If Len(Text
Box2.Text.Trim) <> 0 Then password = "spwd=" + "'" + Text
Box2.Text.Trim + "'" + "," Else password = "" End If If Len(username) <> 0 And Len(password) <> 0 Then temp = username + password Msg
Box(temp.Length) temp = Mid(temp,1,temp.Length - 3) Msg
Box("temp" + temp) Msg
Box("current" + DataGridView1.CurrentRow.Cells(1).Value) Else temp = "" End If Dim strConn = "Data Source=192.168.1.110/orcl;User ID=test;Password=orcl" Dim dbcmd As OracleCommand Dim dbConnection As OracleConnection 'If username.Length = 0 And password = 0 Then Try dbConnection = New OracleConnection(strConn) dbConnection.Open() dbcmd = dbConnection.CreateCommand Dim temp2 As String temp2 = "update student set " + temp + " where sname=" + "'" + DataGridView1.CurrentRow.Cells(1).Value + "'" dbcmd.CommandText = temp2 Msg
Box(temp2) 'dbConnection.BeginTransaction() dbcmd.ExecuteNonQuery() '返回改动的row行数 Catch ex As Exception Msg
Box("
修改失败") Exit Sub End Try ' Else ' Msg
Box("请填入要
修改的参数") 'End If End Sub