尝试打开 MySQL 连接时可能导致 KeyNotFoundException 的原因 [英] What may cause the KeyNotFoundException when trying to open a MySQL connection

问题描述

我尝试使用 C# 代码连接我的数据库，但在调试器访问 MySqlConnection Open 方法时收到 KeyNotFoundException.

我已经尝试将我的 connectionString 更改为另一个模板，重新启动我的 SQL 服务器，并手动验证我的服务器详细信息(用户名、密码等...)

//设置我的连接数据私有无效初始化(){服务器 = "127.0.0.1";数据库 = "数据库";uid = "root";密码 = "123456";字符串连接字符串；connectionString = "SERVER=" + 服务器 + ";"+数据库="+数据库 + ";"+ "uid=" + uid + ";"+ "PWd=" + 密码 + ";";connection = new MySqlConnection(connectionString);}//打开连接私人布尔OpenConnection(){尝试 {connection.Open();//这是我得到异常的地方返回真；}}

因为我除了连接，我得到了下一个例外:

<块引用>

System.Collections.Generic.KeyNotFoundException:字典中不存在给定的键.在 System.Collections.Generic.Dictionary`2.get_Item(TKey 键)在 MySql.Data.MySqlClient.CharSetMap.GetCharacterSet(DBVersion 版本，字符串 CharSetName)在 MySql.Data.MySqlClient.CharSetMap.GetEncoding(DBVersion 版本，字符串 CharSetName)在 MySql.Data.MySqlClient.Driver.Configure(MySqlConnection 连接)在 MySql.Data.MySqlClient.MySqlConnection.Open()在 sqlTesting.DBConnect.OpenConnection() 在 d:\Users\moshe\Documents\Visual Studio 2015\Projects\sqlTesting\sqlTesting\DBConnect.cs:line 40

<预><代码>

解决方案

您应该尝试在 General 下的 Options 选项卡中删除 collat​​ion-server 设置code> 设置并重新启动您的 MySQL 服务器以解决此问题.

或

您可以简单地将 charset 添加到连接字符串中:

Server=127.0.0.1;Port=3306;Database=database;User ID=root;Password=123456;CharSet=utf8;

或

如果您的框架是 .NET，那么您需要做的就是确保您的MySql.Data.dll"与相应版本保持同步.

I trying to connect my database using C# code, but getting a KeyNotFoundException when the debugger gets to MySqlConnection Open method.

I Have tried changing my connectionString to another template, restarting my SQL server, and manually validating my server details (Username, Password ETC...)

//setting my connection data
private void Initialize() {
    server = "127.0.0.1";
    database = "database";
    uid = "root";
    password = "123456";
    String connectionString;
    connectionString = "SERVER=" + server + ";" + "DATABASE=" +
    database + ";" + "Uid=" + uid + ";" + "PWd=" + password + ";";
    connection = new MySqlConnection(connectionString);
}


//Opening the connection
private bool OpenConnection() {
    try {
        connection.Open();//This is where I get my Exception
        return true;
    }
}

As I except connection I am getting the next Exception:

System.Collections.Generic.KeyNotFoundException: The given key was not present in the dictionary. at System.Collections.Generic.Dictionary`2.get_Item(TKey key) at MySql.Data.MySqlClient.CharSetMap.GetCharacterSet(DBVersion version, String CharSetName) at MySql.Data.MySqlClient.CharSetMap.GetEncoding(DBVersion version, String CharSetName) at MySql.Data.MySqlClient.Driver.Configure(MySqlConnection connection) at MySql.Data.MySqlClient.MySqlConnection.Open() at sqlTesting.DBConnect.OpenConnection() in d:\Users\moshe\Documents\Visual Studio 2015\Projects\sqlTesting\sqlTesting\DBConnect.cs:line 40

解决方案

You should try removing collation-server settings in your Options tab under General settings and restart your MySQL server to resolve this issue.

OR

You can simply add the charset to the connection string:

Server=127.0.0.1;Port=3306;Database=database;User ID=root;Password=123456;CharSet=utf8;

OR

If your framework is .NET, then all you need to do is to make sure that your 'MySql.Data.dll' is up to date with the corresponding version.

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