VB - MySql 从数据库中选择
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VB - MySql select from a database
提问by WireCoder
This is how my form looks like - image.
这就是我的表单的样子 -图像。
When form loads, I would like to retrieve the player data whose usernameis in the Label1, so I could display its pointsin the Label2.
当加载窗体时，我想获取玩家数据，其username是在Label1，所以我可以显示其points在Label2。
Here's my code so far:
到目前为止，这是我的代码：
Dim conn As MySqlConnection
conn = New MySqlConnection("server=REMOVED;Port=REMOVED; user id=REMOVED; password=REMOVED; database=REMOVED")
Dim username As Boolean = True
conn.Open()
Dim sqlquery As String = "SELECT Name FROM NewTable WERE Name='" & My.Settings.Name & "';"
Dim data As MySqlDataReader
Dim adapter As New MySqlDataAdapter
Dim command As New MySqlCommand
command.CommandText = sqlquery
command.Connection = conn
adapter.SelectCommand = command
data = command.ExecuteReader
While data.Read()
Label1.Text = data(1).ToString
Label2.Text = data(3).ToString
End While
data.Close()
conn.Close()
Any help would be much appreciated.
任何帮助将非常感激。
采纳答案by John Woo
You should parameterized your query to avoid sql injection, Usingfor proper object disposal, Try-Catchblock to handle the exception properly.
您应该参数化您的查询以避免 sql 注入， Using为了正确处理对象，请Try-Catch阻止以正确处理异常。
Dim connString As String = "server=REMOVED;Port=REMOVED; user id=REMOVED; password=REMOVED; database=REMOVED"
Dim sqlQuery As String = "SELECT Name, Points FROM NewTable WHERE Name = @uname"
Using sqlConn As New MySqlConnection(connString)
Using sqlComm As New MySqlCommand()
With sqlComm
.Connection = sqlConn
.Commandtext = sqlQuery
.CommandType = CommandType.Text
.Parameters.AddWithValue("@uname", My.Settings.Name)
End With
Try
sqlConn.Open()
Dim sqlReader As MySqlDataReader = sqlComm.ExecuteReader()
While sqlReader.Read()
Label1.Text = sqlReader("Name").ToString()
Label2.Text = sqlReader("Points").ToString()
End While
Catch ex As MySQLException
' add your exception here '
End Try
End Using
End Using
