这段老提示必须声明标量变量"@MemberName"

Question

public bool IsReged(string MemberName)
        {
            StringBuilder strSQL = new StringBuilder();
            strSQL.Append("select count(*) From Member");
            strSQL.Append(" Where MemberName=@MemberName");
            SqlParameter[] parameters = 
                {
                    new SqlParameter("@MemberName",SqlDbType.VarChar,15)
                };
            parameters[0].Value = MemberName;
            return SQLHelper.Exists(strSQL.ToString(), parameters);
        }

Answer 1

你确实没有定义那个变量 。
public bool IsReged(string MemberName)
        {
            StringBuilder strSQL = new StringBuilder();
            strSQL.Append("select count(*) From Member");
            strSQL.Append(" Where MemberName='");@MemberName");
            strSQL.AppendMemberName.ToString());
            strSQL.Append(" '");          
            return SQLHelper.Exists(strSQL.ToString());
        }
/////////////////////////////////////////////////////////////////////////
public bool IsReged(string MemberName)
        {
            StringBuilder strSQL = new StringBuilder();
            strSQL.Append("declare @MemberName varchar(50)  ");
            strSQL.Append("select count(*) From Member");
            strSQL.Append(" Where MemberName='");@MemberName");
            strSQL.AppendMemberName.ToString());
            strSQL.Append(" '");          
            return SQLHelper.Exists(strSQL.ToString());
        }

Answer 2

试了..还是不行..那段在Access下没有问题..在SqlServer下就报错...

Answer 3

看一下SQLHelper.Exists()方法，估计有问题。

Answer 4

public static bool Exists(string SQLString, params SqlParameter[] cmdParms)
        {
            object obj = GetSingle(SQLString, cmdParms);
            int CmdResult;
            if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
            {
                CmdResult = 0;
            }
            else
            {
                CmdResult = int.Parse(obj.ToString());
            }
            if (CmdResult == 0)
            {
                return false;
            }
            else
            {
                return true;
            }
        }public static object GetSingle(string SQLString, params SqlParameter[] cmdParms)
        {
            SqlConnection Conn = new SqlConnection(ConnString);
            SqlCommand Cmd = new SqlCommand();
            try
            {
                PrepareCommand(Cmd, Conn, null, SQLString, cmdParms);
                object obj = Cmd.ExecuteScalar();
                Cmd.Parameters.Clear();
                if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
                {
                    return null;
                }
                else
                {
                    return obj;
                }
            }
            catch (SqlException Ex)
            {
                throw new Exception(Ex.Message);
            }
        }