你有错误语法VB.Net MySql

Question

我想更新vb.net中的mysql数据库表，我尝试和我有问题。这是我的源

MysqlConn = New MySqlConnection 
    MysqlConn.ConnectionString = 
    "server=db4free.net;port=3306;userid=***;password=***;database=***" 
    Dim Reader As MySqlDataReader 
    Try 
     MysqlConn.Open() 
     Dim Query As String 
     Query = "update member set (Name='" & Val(TextBox1.Text) + Val(TextBox6.Text) & "' WHERE Username='" & TextBox8.Text & "'" 
     Command = New MySqlCommand(Query, MysqlConn) 
     Reader = Command.ExecuteReader 
     MysqlConn.Close() 
    Catch ex As Exception 
     MsgBox(ex.Message) 
    Finally 
     MysqlConn.Dispose() 
    End Try 

如果我这样做源，我有这样的

Answer 1

TextBox1.Text = 10 
TextBox6.Text = 20 
TextBox8.Text = John 

下面的错误代码是你有什么

"update member set (Name='" & Val(TextBox1.Text) + Val(TextBox6.Text) & "' WHERE Username='" & TextBox8.Text & "'" 

渲染：

update member set (Name='30' WHERE Username='John' 

-

你可能想要的是卸下支架

"update member set Name='" & Val(TextBox1.Text) + Val(TextBox6.Text) & "' WHERE Username='" & TextBox8.Text & "'" 

导致：

update member set Name='30' WHERE Username='John' 

我给你的建议作为构建这些字符串的偏爱是对参数的详细经常分开。它使事情整洁而简单。

例如：

dim x as string = (Val(TextBox1.Text) + Val(TextBox6.Text)).tostring 
dim cmd as string = 
"update member " & 
"set Name=" & "'" & x & "' " & 
"WHERE Username=" & "'" & TextBox8.Text & "'"