[英]Insert and Update mysql values c#
我在我的twitch機器人中使用此代碼對消息進行計數,並將它們每分鍾幾次存儲到數據庫中。
因此,我擁有的當前代碼確實從數據庫中獲取了我想要的值,但是我無法正確更新或插入值。 insert_cmd確實會執行,但是數據庫中的值與我嘗試插入的值不對應。 受影響的行確實返回應該受到影響的行的正確答案。 另外,當我寫出insert_cmd字符串時,它看起來確實正確。
private static void update_messages()
{
try
{
MySql.Data.MySqlClient.MySqlConnection mysql_connection = new MySql.Data.MySqlClient.MySqlConnection();
mysql_connection.ConnectionString = mysql_connection_string;
mysql_connection.Open();
//build query string
string select_cmd = "SELECT * FROM taperen.messages where username in (";
foreach(CountData cd in chat_messages)
{
//Console.WriteLine(cd.username);
select_cmd += "\'" + cd.username + "\',";
}
if(select_cmd == "SELECT * FROM taperen.messages where username in (")
{
mysql_connection.Close();
return;
}
select_cmd = select_cmd.TrimEnd(select_cmd[select_cmd.Length - 1]);
select_cmd += ");";
//Console.WriteLine(select_cmd);
MySql.Data.MySqlClient.MySqlCommand myCommand = mysql_connection.CreateCommand();
myCommand.CommandText = select_cmd;
MySql.Data.MySqlClient.MySqlDataReader reader = myCommand.ExecuteReader();
string insert_cmd = "";
while (reader.Read())
{
string username = reader["username"].ToString();
int index = chat_messages.FindIndex(x => x.username.Equals(username));
int current_online_count = chat_messages[index].online_count;
int current_offline_count = chat_messages[index].offline_count;
int db_online_count = (int)reader["online_count"];
int db_offline_count = (int)reader["offline_count"];
int new_online_count = current_online_count + db_online_count;
int new_offline_count = current_offline_count + db_offline_count;
insert_cmd += $"UPDATE `taperen`.`messages` SET `online_count`='{new_online_count}', `online_count`='{new_offline_count}' WHERE `id`='{reader["id"]}';";
chat_messages.RemoveAt(index);
//Console.WriteLine(username);
}
reader.Close();
mysql_connection.Close();
foreach(CountData cd in chat_messages)
{
insert_cmd += $"INSERT INTO `taperen`.`messages` (`username`, `online_count`, `offline_count`) VALUES ('{cd.username}', '{cd.online_count}', '{cd.offline_count}');";
}
mysql_connection.Open();
//Console.WriteLine(insert_cmd);
myCommand.CommandText = insert_cmd;
int affectedRows = myCommand.ExecuteNonQuery();
Console.WriteLine(affectedRows);
myCommand.Dispose();
mysql_connection.Close();
}
catch (MySql.Data.MySqlClient.MySqlException ex)
{
Console.WriteLine(ex.Message);
}
}
CountData類如下所示:
public class CountData
{
public string username { get; set; }
public int online_count { get; set; }
public int offline_count { get; set; }
}
該數據庫如下所示:
另外,如果我在代碼中做了其他愚蠢的事情,我也很感謝您能帶一些技巧:)
在這一行中,您要設置online_count
兩次,第二個實例(大概)應該是offline_count
。
insert_cmd + = $ “UPDATE
taperen
。messages
SETonline_count
= '{} new_online_count',online_count
= '{} new_offline_count' WHEREid
= '{讀取器[ ”ID“]}',”;
您需要挑選出由代碼生成的查詢。 然后直接將其運行到Mysql中,然后比較它返回的內容。 它看起來是mysql返回最后執行查詢的行。 當您先組合更新,然后組合插入時,因此將影響插入的行。 但是您可以通過直接運行查詢來確認。 確保注釋掉這樣的代碼:
// int受影響的行= myCommand.ExecuteNonQuery();
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.