使用輸出參數執行MySqlCommand（StoredProcedure）

Question

我無法弄清楚如何使用Connector/NET 3.6.5提供的MySQLCommand。基本上這裏是我使用的代碼和我運行ExecuteNonQuery時得到的異常。我在這裏做錯了什麼？我沒有想法離開:(

var connection = GetConnection(); 
connection.Open(); 

var command = new MySqlCommand("PredictPaperRankInInterval", connection); 
command.CommandType = CommandType.StoredProcedure; 
command.Parameters.Add(new MySqlParameter("p_journalId", SqlDbType.VarChar) { Value = "test" }); 
command.Parameters.Add(new MySqlParameter("p_publishDate", SqlDbType.DateTime) { Value = paper.PublishDate }); 
command.Parameters.Add(new MySqlParameter("p_intervalInDays", SqlDbType.Int) { Value = 7 }); 
command.Parameters.Add(new MySqlParameter("p_viewsCount", SqlDbType.Int) { Value = paper.ViewsCount }); 
var rank = new MySqlParameter("p_rank", SqlDbType.Int) { Direction = ParameterDirection.Output }; 
command.Parameters.Add(rank); 

command.ExecuteNonQuery(); 

異常

Input string was not in a correct format. 

DDL

CREATE PROCEDURE `PredictPaperRankInInterval`(IN p_journalId VARCHAR(32), 
               IN p_publishDate DATETIME, 
               IN p_intervalInDays INT, 
               IN p_viewsCount INT, 
               OUT p_rank INT) 

Answer 1

MySqlCommand command = new MySqlCommand("PredictPaperRankInInterval", con); 
command .CommandType = System.Data.CommandType.StoredProcedure;