VB.NET:使用变量生成MySQL查询
我已经编写了下面的代码来更新我的表,但它不起作用VB.NET:使用变量生成MySQL查询,mysql,.net,vb.net,variables,Mysql,.net,Vb.net,Variables,我已经编写了下面的代码来更新我的表,但它不起作用 sqlstr = "UPDATE Student SET " & S & " = @field1, " & L & " = @field2, " & R & " =@field3, " & W & "=@field4 WHERE Code='" & StdID & "'" DBCmd = New MySql.Data.MySqlClient.MySqlCommand(
sqlstr = "UPDATE Student SET " & S & " = @field1, " & L & " = @field2, " & R & " =@field3, " & W & "=@field4 WHERE Code='" & StdID & "'"
DBCmd = New MySql.Data.MySqlClient.MySqlCommand(sqlstr, DBConn)
With DBCmd
.Parameters.AddWithValue("@field1", CB_S.SelectedItem)
.Parameters.AddWithValue("@field2", CB_L.SelectedItem)
.Parameters.AddWithValue("@field3", CB_R.SelectedItem)
.Parameters.AddWithValue("@field4", CB_W.SelectedItem)
End With
DBCmd.Dispose()
其中S、L、R和W是字符串:S1、L1、R1、W1。
StdID是一个整数。CB_S、CB_L、CB_R和CB_W是组合框
谁能告诉我出了什么问题吗?您没有打开
连接
并调用ExecuteNonQUery()
。还参数化了code
sqlstr = "UPDATE Student SET " & S & " = @field1, " & L & " = @field2, " & R & " =@field3, " & W & "=@field4 WHERE Code=@code"
DBCmd = New MySql.Data.MySqlClient.MySqlCommand(sqlstr, DBConn)
With DBCmd
.Parameters.AddWithValue("@field1", CB_S.SelectedItem)
.Parameters.AddWithValue("@field2", CB_L.SelectedItem)
.Parameters.AddWithValue("@field3", CB_R.SelectedItem)
.Parameters.AddWithValue("@field4", CB_W.SelectedItem)
.Parameters.AddWithValue("@code", StdID)
End With
DBConn.Open()
DBCmd.ExecuteNonQuery()
哦,太尴尬了!!谢谢