执行存储过程并通过输出和sql参数将行计数返回给代码

Question

我有以下代码通过会话变量匹配用户输入.如果会话变量中的数据与数据库中的数据匹配,则存储过程将返回行计数.

一切正常,除了我想要返回Row Count,它总是一行:简而言之,你访问一个表单,添加信息并点击提交.数据存储在会话中,存储过程在匹配时返回数据.

即使程序正常工作,intRecCount变量也始终为零而不是行计数.

存储过程:

CREATE PROCEDURE [dbo].[uspConfirmation]

    @RecordID CHAR(36),
    @LName VARCHAR(30),
    @FName VARCHAR(30),
    @MInit CHAR(1),
    @RecordCount INT OUTPUT
AS

SELECT * FROM Registration
WHERE RecordID = @RecordID AND
      LName = @LName AND
      FName = @FName AND
      MInit = @MInit

SET @RecordCount = @@ROWCOUNT

RETURN

方法/代码:

public static DataSet Confirmation()
{ 
SqlCommand cmdSQL = new SqlCommand("uspConfirmation", Connection);
cmdSQL.CommandType = CommandType.StoredProcedure;

cmdSQL.Parameters.Add(new SqlParameter("@RecordID", SqlDbType.VarChar, 36));
cmdSQL.Parameters["@RecordID"].Direction = ParameterDirection.Input;
cmdSQL.Parameters["@RecordID"].Value = RecordIDSession;

cmdSQL.Parameters.Add(new SqlParameter("@LName", SqlDbType.VarChar, 30));
cmdSQL.Parameters["@LName"].Direction = ParameterDirection.Input;
cmdSQL.Parameters["@LName"].Value = LNameSession;

cmdSQL.Parameters.Add(new SqlParameter("@FName", SqlDbType.VarChar, 30));
cmdSQL.Parameters["@FName"].Direction = ParameterDirection.Input;
cmdSQL.Parameters["@FName"].Value = FNameSession;

cmdSQL.Parameters.Add(new SqlParameter("@MInit", SqlDbType.Char, 1));
cmdSQL.Parameters["@MInit"].Direction = ParameterDirection.Input;
cmdSQL.Parameters["@MInit"].Value = MNameSession;

cmdSQL.Parameters.Add(new SqlParameter("@RecordCount", SqlDbType.Int));
cmdSQL.Parameters["@RecordCount"].Direction = ParameterDirection.Output;

...然后通过输出变量保存行计数的变量...

Int32 intRecCount = Convert.ToInt32(cmdSQL.Parameters["@RecordCount"].Value);

SqlDataAdapter da = new SqlDataAdapter(cmdSQL);
DataSet ds = new DataSet();
da.Fill(ds);

try {
    Connection.Open();
    cmdSQL.ExecuteNonQuery();
}
catch (Exception ex) {   
    dbMsg = ex.Message; 
}
finally {
    Connection.Close();
    cmdSQL.Dispose();
    cmdSQL.Parameters.Clear();
}
return ds;
}

Answer 1

在执行查询之前,您需要访问输出参数的值.因此,在执行查询之后,在清除参数之前移动此行,例如:

//VARIABLE TO HOLD ROW COUNT VIA OUTPUT VIARABLE 
Int32 intRecCount = Convert.ToInt32(cmdSQL.Parameters["@RecordCount"].Value);

所以你的方法代码是:

public static DataSet Confirmation()
{ 
SqlCommand cmdSQL = new SqlCommand("uspConfirmation", Connection);
cmdSQL.CommandType = CommandType.StoredProcedure;

cmdSQL.Parameters.Add(new SqlParameter("@RecordID", SqlDbType.VarChar, 36));
cmdSQL.Parameters["@RecordID"].Direction = ParameterDirection.Input;
cmdSQL.Parameters["@RecordID"].Value = RecordIDSession;

cmdSQL.Parameters.Add(new SqlParameter("@LName", SqlDbType.VarChar, 30));
cmdSQL.Parameters["@LName"].Direction = ParameterDirection.Input;
cmdSQL.Parameters["@LName"].Value = LNameSession;

cmdSQL.Parameters.Add(new SqlParameter("@FName", SqlDbType.VarChar, 30));
cmdSQL.Parameters["@FName"].Direction = ParameterDirection.Input;
cmdSQL.Parameters["@FName"].Value = FNameSession;

cmdSQL.Parameters.Add(new SqlParameter("@MInit", SqlDbType.Char, 1));
cmdSQL.Parameters["@MInit"].Direction = ParameterDirection.Input;
cmdSQL.Parameters["@MInit"].Value = MNameSession;

cmdSQL.Parameters.Add(new SqlParameter("@RecordCount", SqlDbType.Int));
cmdSQL.Parameters["@RecordCount"].Direction = ParameterDirection.Output;



SqlDataAdapter da = new SqlDataAdapter(cmdSQL);
DataSet ds = new DataSet();
da.Fill(ds);
Int32 intRecCount = 0;
try
{
    Connection.Open();
    cmdSQL.ExecuteNonQuery();
    //VARIABLE TO HOLD ROW COUNT VIA OUTPUT VIARABLE
    intRecCount = Convert.ToInt32(cmdSQL.Parameters["@RecordCount"].Value);

}
catch (Exception ex)
{
    dbMsg = ex.Message;
}
finally
{
    Connection.Close();
    cmdSQL.Dispose();
    cmdSQL.Parameters.Clear();
}


return ds;
}