c# - DataAdapter Fill 没有从 Command 对象获取参数

Question

我正在尝试从 DataAdapter 填充数据表，但数据库不断报告没有为查询指定参数...

这是我的代码:

    #region "Properties"
    public string sql { get; protected set; }
    public CommandType cType { get; protected set; }
    public List<MySqlParameter> args { get; protected set; }
    public string rValue { get; protected set; }

    private MySqlConnection conn;

    private string server = "127.0.0.1";
    private string database = "stman";
    private string user = "root";
    private string password = "root";
    #endregion

    #region "Constructor Logic"
        public Database(string CommandText, CommandType CommandType, List<MySqlParameter> Parameters, string ReturnParameter = "")
        {
            buildConnection();

            sql = CommandText;
            cType = CommandType;
            args = Parameters;
            rValue = ReturnParameter;
        }

        public Database(string CommandText, CommandType CommandType)
        {
            buildConnection();

            sql = CommandText;
            cType = CommandType;
        }

        private void buildConnection()
        {
            StringBuilder sb = new StringBuilder();
            sb.Append(String.Format("data source={0}; initial catalog={1}; user id={2}; password={3};", server, database, user, password));

            conn = new MySqlConnection(sb.ToString());
        }
    #endregion

    public DataTable GetDataTable()
    {
        DataTable dt = new DataTable();
        MySqlDataAdapter da = new MySqlDataAdapter();

        using (MySqlCommand cmd = new MySqlCommand(sql, conn))
        {
            if (args.Count > 0)
            {
                cmd.Parameters.AddRange(args.ToArray());
            }

            da.SelectCommand = cmd;
            da.Fill(dt);
        }

        if (dt.Rows.Count > 0)
        {
            return dt;
        }
        else
        {
            return null;
        }
    }

GetDataTable函数读取 List<MySqlParameter>用于查询所需的参数 - 此列表在调用代码中定义。

当时da.Fill(dt);被命中，MySqlCommand 确实具有相关查询的正确参数，并且从堆栈跟踪(见下文)判断，似乎确实从 mysql 获取数据的尝试确实通过了，并且实际上是 mysql 正在发送返回此错误:

这是堆栈跟踪:

[MySqlException (0x80004005): Incorrect number of arguments for PROCEDURE stman.Users_SelectByEmailAndPassword; expected 2, got 0] MySql.Data.MySqlClient.MySqlStream.ReadPacket() +383 MySql.Data.MySqlClient.NativeDriver.GetResult(Int32& affectedRow, Int64& insertedId) +116 MySql.Data.MySqlClient.Driver.GetResult(Int32 statementId, Int32& affectedRows, Int64& insertedId) +54 MySql.Data.MySqlClient.Driver.NextResult(Int32 statementId, Boolean force) +145 MySql.Data.MySqlClient.MySqlDataReader.NextResult() +1258 MySql.Data.MySqlClient.MySqlCommand.ExecuteReader(CommandBehavior behavior) +2364 MySql.Data.MySqlClient.MySqlCommand.ExecuteDbDataReader(CommandBehavior behavior) +41 System.Data.Common.DbCommand.System.Data.IDbCommand.ExecuteReader(CommandBehavior behavior) +10 System.Data.Common.DbDataAdapter.FillInternal(DataSet dataset, DataTable[] datatables, Int32 startRecord, Int32 maxRecords, String srcTable, IDbCommand command, CommandBehavior behavior) +140 System.Data.Common.DbDataAdapter.Fill(DataTable[] dataTables, Int32 startRecord, Int32 maxRecords, IDbCommand command, CommandBehavior behavior) +160 System.Data.Common.DbDataAdapter.Fill(DataTable dataTable) +108 stman.Database.GetDataTable() in d:\Development\stman\stman\App_Code\Database.cs:85 stman.LoginContext.DoLogin() in d:\Development\stman\stman\App_Code\LoginContext.cs:45 stman.Login.processLogin() in d:\Development\stman\stman\Login.aspx.cs:40 stman.Login.btnLogin_Click(Object sender, EventArgs e) in d:\Development\stman\stman\Login.aspx.cs:32 System.Web.UI.WebControls.Button.OnClick(EventArgs e) +9553594 System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) +103 System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +10 System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +13 System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +35 System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1724

我多年来一直像这样填充数据表，这是我第一次遇到这个错误。我不知道为什么会发生这种情况，也不知道如何解决。

谁能帮我弄清楚参数的去向吗？

编辑
回应雷南的评论:

参数名称相同。
查询文本(在本例中为存储过程的名称)被传递到 sql实例化此类时的属性。
最后，我的 IDE 的配色方案就是 VS2012 深色主题

Answer 1

好吧，这不是我在代码中所做的事情的问题，这是我没有做的事情的问题。

虽然代码中没有真正的错误，但它没有指定 MySqlCommand 的 CommandType。

我通过添加此行(指定对象要使用的 CommandType)来修复此问题:

cmd.CommandType = cType;

完整代码如下:

#region "Properties"
public string sql { get; protected set; }
public CommandType cType { get; protected set; }
public List<MySqlParameter> args { get; protected set; }
public string rValue { get; protected set; }

private MySqlConnection conn;

private string server = "127.0.0.1";
private string database = "stman";
private string user = "root";
private string password = "root";
#endregion

#region "Constructor Logic"
    public Database(string CommandText, CommandType CommandType, List<MySqlParameter> Parameters, string ReturnParameter = "")
    {
        buildConnection();

        sql = CommandText;
        cType = CommandType;
        args = Parameters;
        rValue = ReturnParameter;
    }

    public Database(string CommandText, CommandType CommandType)
    {
        buildConnection();

        sql = CommandText;
        cType = CommandType;
    }

    private void buildConnection()
    {
        StringBuilder sb = new StringBuilder();
        sb.Append(String.Format("data source={0}; initial catalog={1}; user id={2}; password={3};", server, database, user, password));

        conn = new MySqlConnection(sb.ToString());
    }
#endregion

public DataTable GetDataTable()
{
    DataTable dt = new DataTable();
    MySqlDataAdapter da = new MySqlDataAdapter();

    using (MySqlCommand cmd = new MySqlCommand(sql, conn))
    {
        if (args.Count > 0)
        {
            cmd.Parameters.AddRange(args.ToArray());
        }

        cmd.CommandType = cType;

        da.SelectCommand = cmd;
        da.Fill(dt);
    }

    if (dt.Rows.Count > 0)
    {
        return dt;
    }
    else
    {
        return null;
    }
}