Question

我想为select语句编写参数化查询。但它给出了“必须声明变量'@'的例外情况。”如何声明这个变量。

我的代码如下：

SqlConnection con = null;
        SqlCommand cmd = null;
        try
        {
            //int @[MONTH_FOR], @[YEAR_FOR];
            con = new SqlConnection("Data Source=192.168.10.3;Initial Catalog=GPSTrainees;user id=gp;password=gp");
            con.Open();
            string select = @"SELECT [COMPONENT_NAME] ,[COMPONENT_AMOUNT] 
                            FROM [GoalPlanForTrainees].[gp].[TEAM_FUNDS_DETAILS] 
                            WHERE [MONTH_FOR] = @[MONTH_FOR] AND [YEAR_FOR] = @[YEAR_FOR]";
            cmd = new SqlCommand(select, con);
            cmd.Parameters.Add(new SqlParameter("@[MONTH_FOR]", Convert.ToInt32( TextBox1.Text.Trim())));
            cmd.Parameters.Add(new SqlParameter("@[YEAR_FOR]",Convert.ToInt32(TextBox2.Text.Trim())));
            DataSet ds = new DataSet();
            SqlDataAdapter adp = new SqlDataAdapter(select, con);
            adp.Fill(ds);
            GridView1.DataSource = ds;
            GridView1.DataBind();
        }
        catch (Exception ex)
        {
        }
        finally
        {
            if (con != null)
            {
                con.Close();
            }
        }`enter code here`

Answer 1

将变量声明放在sql语句中。所以移动int @ [MONTH_FOR]，@ [YEAR_FOR]; 至 @“int @ [MONTH_FOR]，@ [YEAR_FOR]; SELECT [COMPONENT_NAME]，[COMPONENT_AMOUNT] FROM [GoalPlanForTrainees]。[gp]。[TEAM_FUNDS_DETAILS] WHERE [MONTH_FOR] = @ [MONTH_FOR]和[YEAR_FOR] = @ [YEAR_FOR ]“;

Cheers Tigger

Answer 2

创建参数时，请删除参数名称前面的“@”。像这样：

cmd.Parameters.Add(new SqlParameter("[MONTH_FOR]", Convert.ToInt32(TextBox1.Text.Trim())));

希望这应该有所帮助。

Answer 3

试试这个

int MONTH_FOR=@monthFor
command.Parameters.Add(MONTH_FOR, SqlDbType.int).Value = value

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3 个答案: