Mysql 如何通过dropdownlist从数据库中删除值？

基本上，我试图让用户通过从下拉列表中选择员工的姓名并单击“完成”来删除与员工相关的数据，但我不断收到错误消息，如

附近语法不正确

但是我设置了检查点，可以看到没有任何价值被发现，所以我想知道有没有人知道我错在哪里

 Dim Con As SqlConnection
    Dim cmd As SqlCommand
    Dim recordsAffected As String
    Dim cmdstring As String = "Delete StaffID, FullName, Gender, Age, Driver, StartDate, ContactNumber, Waistcoat WHERE FullName = DropDownList1.SelectedValue"
    Con = New SqlConnection("Data Source=OISINMCGRANN-PC\SQLEXPRESS;Initial Catalog=YellowDoor;Integrated Security=True")
    cmd = New SqlCommand(cmdstring, Con)
    Con.Open()
    RecordsAffected = cmd.ExecuteNonQuery()
    Con.Close()
End Sub

我尝试过这个，但没有引用dropdownlist：

   Dim Con As SqlConnection
        Dim cmd As SqlCommand
        Dim recordsAffected As String
        Dim cmdstring As String = "Delete StaffID, FullName, Gender, Age, Driver, StartDate, ContactNumber, Waistcoat WHERE FullName =" + DropDownList1.SelectedValue
        Con = New SqlConnection("Data Source=OISINMCGRANN-PC\SQLEXPRESS;Initial Catalog=YellowDoor;Integrated Security=True")
        cmd = New SqlCommand(cmdstring, Con)
        Con.Open()
        RecordsAffected = cmd.ExecuteNonQuery()
        Con.Close()
    End Sub

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如果您使用的是MySql，那么查询应该是

DELETE FROM table_name
WHERE some_column = some_value 

我在您的查询中没有看到任何表名

Delete [FROM TABLE?] WHERE FullName =" + DropDownList1.SelectedValue

---

使用参数化查询并避免

或

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对不起，是的，我很傻，我一直在玩这个查询太多次了，那次我忽略了它-我只是复制了你的查询并添加了表，而且附近的语法也不正确，全名必须用单引号括起来。删除[表？]中的FullName='您的姓名'。此外，您还暴露于sql注入，因此请务必尝试使用它，但仍然无法使用'Dim Con As SqlConnection Dim cmd As SqlCommand Dim records受影响As String Dim cmdstring As String=DELETE[Staff Table]StaffID、全名、性别、年龄、驱动程序、起始日期、联系人编号、，“全名”+DropDownList1.SelectedValue Con=New-SqlConnectionData-Source=OISINMCGRANN-PC\SQLEXPRESS的背心；初始目录=黄色门；integratedsecurity=True cmd=New SqlCommandcmdstring，Con Con.Open recordsafected=cmd.ExecuteNonQuery Con.Close End Sub“从人员表中删除，其中FullName=”+DropDownList1.SelectedValue+”；但您必须使用参数化查询。这仅适用于testingdelete from table name，其中FullName='+DropDownList 1。SelectedValue+'尝试此操作，这不是使用参数化查询的好做法

 Dim cmdstring As String = "Delete from tablename WHERE FullName =@FullName";

cmd.Parameters.AddWithValue("FullName",DropDownList1.SelectedValue);

cmd.Parameters.Add("@FullName", SqlDbType.VarChar, 50).Value =DropDownList1.SelectedValue;