时间:2021-07-01 10:21:17 帮助过:39人阅读
请问如何使用MySqlClient实现如下功能:
已知连接参数
Public sql As String = "server=192.168.2.97;user id=root;password=root;persistsecurityinfo=True;port=3306;database=school"
表名 children
1) 读取 Index=1 行 age 值
2) 写入一行新数据“Index=7;name=ght;age=12;sex=girl”
3) 将 Index=4 行的 age 数据修改为12
4) 查询表中 age=12 的数据行有多少
5) 将 Index=4 行数据从数据库中删除
现有资料都是通过ADODC连接,但是项目要求使用MySqlClient来做
现有已经实现的功能1,2,的源码如下(非此题代码,是我的项目源码),但是其它的不会写了
'数据库相关 Public sql As String = "server=192.168.2.97;user id=root;password=nbjgtyndatabase;persistsecurityinfo=True;port=3307;database=nbjgtyn" Public mcn As MySqlConnection = New MySql.Data.MySqlClient.MySqlConnection(sql) Public sqlstr As String = "select * from Zhi_Liu_Ce_Liang where Datatime = '" & DateTime.Now & "'" Public mda As MySqlDataAdapter Public dt As DataTable Public Entry As String = "aaaa" '数据库中存储本机设置的条目查询字 Public astr As String = "select * from Config where Name = '" & Entry & "'" Public mcmd As MySqlCommand Public mdr As MySqlDataReader1) mcn.Open() mcmd = New MySqlCommand(astr, mcn) mdr = mcmd.ExecuteReader mdr.Read() Local_Port = mdr.Item("Port") KeyWord = mdr.Item("Keyword") mcn.Close() 2) mda = New MySqlDataAdapter(sqlstr, mcn) dt = New DataTable mda.Fill(dt) Dim dr As DataRow = dt.NewRow() dr.Item("Number") = sender.Number dr.Item("Datatime") = DateTime.Now dr.Item("Current") = sender.Current dr.Item("Voltage") = sender.Voltage dr.Item("Power") = sender.Power dt.Rows.Add(dr) Dim cb As MySqlCommandBuilder = New MySqlCommandBuilder(mda) mda.Update(dt)