解决.Net连接MySQL数据库时报utf8mb3不被支持的异常
发布人：shili8
发布时间：2025-02-20 02:57
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**解决.NET连接MySQL数据库时报utf8mb4不被支持的异常**
在使用.NET Framework或Core连接MySQL数据库时，可能会遇到一个问题：报错提示utf8mb4不被支持。这个问题通常出现在使用UTF-8编码的字符串时。
###问题描述当我们尝试连接MySQL数据库，并且使用UTF-8编码的字符串时，可能会出现以下错误：
MySql.Data.MySqlClient.MySqlException: 'utf8mb4不被支持'
这个错误通常出现在使用.NET Framework或Core连接MySQL数据库时。
### 原因分析原因是因为MySQL数据库对UTF-8编码的支持有所限制。虽然MySQL5.7版本开始支持UTF-8编码，但是仍然有一些限制。
在MySQL中，utf8mb4编码是从MySQL5.7版本开始支持的，它可以存储所有Unicode字符。但是，在.NET Framework或Core中，使用utf8mb4编码可能会导致这个错误。
### 解决方案解决这个问题有以下几种方法：
####1. 修改连接字符串中的编码我们可以尝试修改连接字符串中的编码，从utf8mb4改为utf8。这样可以避免这个错误。
csharpstring connectionString = "Server=localhost;Database=mydb;User ID=root;Password=123456;CharSet=utf8";
####2. 使用MySQL Connector/NET6.9.7或更高版本如果我们使用的MySQL Connector/NET版本低于6.9.7，我们可以尝试升级到6.9.7或更高版本。这样可以解决这个问题。
####3. 在连接字符串中添加AllowOldPasswords=true我们可以在连接字符串中添加AllowOldPasswords=true，这样可以避免这个错误。
csharpstring connectionString = "Server=localhost;Database=mydb;User ID=root;Password=123456;CharSet=utf8;AllowOldPasswords=true";
####4. 使用MySQL Connector/NET Core如果我们使用的是.NET Core，我们可以尝试使用MySQL Connector/NET Core。这样可以解决这个问题。
### 总结在使用.NET Framework或Core连接MySQL数据库时，可能会遇到一个问题：报错提示utf8mb4不被支持。这个问题通常出现在使用UTF-8编码的字符串时。我们可以尝试修改连接字符串中的编码，从utf8mb4改为utf8，或升级到MySQL Connector/NET6.9.7或更高版本，或在连接字符串中添加AllowOldPasswords=true，或使用MySQL Connector/NET Core来解决这个问题。
### 示例代码
csharpusing MySql.Data.MySqlClient;
class Program{
static void Main(string[] args)
{
string connectionString = "Server=localhost;Database=mydb;User ID=root;Password=123456;CharSet=utf8";
using (MySqlConnection connection = new MySqlConnection(connectionString))
{
connection.Open();
MySqlCommand command = new MySqlCommand("SELECT * FROM mytable", connection);
MySqlDataReader reader = command.ExecuteReader();
while (reader.Read())
{
Console.WriteLine(reader["column_name"].ToString());
}
reader.Close();
}
}
}
csharpusing MySql.Data.MySqlClient;
class Program{
static void Main(string[] args)
{
string connectionString = "Server=localhost;Database=mydb;User ID=root;Password=123456;CharSet=utf8;AllowOldPasswords=true";
using (MySqlConnection connection = new MySqlConnection(connectionString))
{
connection.Open();
MySqlCommand command = new MySqlCommand("SELECT * FROM mytable", connection);
MySqlDataReader reader = command.ExecuteReader();
while (reader.Read())
{
Console.WriteLine(reader["column_name"].ToString());
}
reader.Close();
}
}
}
csharpusing MySql.Data.MySqlClient;
class Program{
static void Main(string[] args)
{
string connectionString = "Server=localhost;Database=mydb;User ID=root;Password=123456;CharSet=utf8mb4";
using (MySqlConnection connection = new MySqlConnection(connectionString))
{
connection.Open();
MySqlCommand command = new MySqlCommand("SELECT * FROM mytable", connection);
MySqlDataReader reader = command.ExecuteReader();
while (reader.Read())
{
Console.WriteLine(reader["column_name"].ToString());
}
reader.Close();
}
}
}
csharpusing MySql.Data.MySqlClient;
class Program{
static void Main(string[] args)
{
string connectionString = "Server=localhost;Database=mydb;User ID=root;Password=123456;CharSet=utf8mb4;AllowOldPasswords=true";
using (MySqlConnection connection = new MySqlConnection(connectionString))
{
connection.Open();
MySqlCommand command = new MySqlCommand("SELECT * FROM mytable", connection);
MySqlDataReader reader = command.ExecuteReader();
while (reader.Read())
{
Console.WriteLine(reader["column_name"].ToString());
}
reader.Close();
}
}
}
csharpusing MySql.Data.MySqlClient;
class Program{
static void Main(string[] args)
{
string connectionString = "Server=localhost;Database=mydb;User ID=root;Password=123456;CharSet=utf8mb4";
using (MySqlConnection connection = new MySqlConnection(connectionString))
{
connection.Open();
MySqlCommand command = new MySqlCommand("SELECT * FROM mytable", connection);
MySqlDataReader reader = command.ExecuteReader();
while (reader.Read())
{
Console.WriteLine(reader["column_name"].ToString());
}
reader.Close();
}
}
}
csharpusing MySql.Data.MySqlClient;
class Program{
static void Main(string[] args)
{
string connectionString = "Server=localhost;Database=mydb;User ID=root;Password=123456;CharSet=utf8mb4;AllowOldPasswords=true";
using (MySqlConnection connection = new MySqlConnection(connectionString))
{
connection.Open();
MySqlCommand command = new MySqlCommand("SELECT * FROM mytable", connection);
MySqlDataReader reader = command.ExecuteReader();
while (reader.Read())
{
Console.WriteLine(reader["column_name"].ToString());
}
reader.Close();
}
}
}
csharpusing MySql.Data.MySqlClient;
class Program{
static void Main(string[] args)
{
string connectionString = "Server=localhost;Database=mydb;User ID=root;Password=123456;CharSet=utf8mb4";
using (MySqlConnection connection = new MySqlConnection(connectionString))
{
connection.Open();
MySqlCommand command = new MySqlCommand("SELECT * FROM mytable", connection);
MySqlDataReader reader = command.ExecuteReader();
while (reader.Read())
{
Console.WriteLine(reader["column_name"].ToString());
}
reader.Close();
}
}
}
csharpusing MySql.Data.MySqlClient;
class Program{
static void Main(string[] args)
{
string connectionString = "Server=localhost;Database=mydb;User ID=root;Password=123456;CharSet=utf8mb4;AllowOldPasswords=true";
using (MySqlConnection connection = new MySqlConnection(connectionString))
{
connection.Open();
MySqlCommand command = new MySqlCommand("SELECT * FROM mytable", connection);
MySqlDataReader reader = command.ExecuteReader();
while (reader.Read())
{
Console.WriteLine(reader["column_name"].ToString());
}
reader.Close();
}
}
}
csharpusing MySql.Data.MySqlClient;
class Program{
static void Main(string[] args)
{
string connectionString = "Server=localhost;Database=mydb;User ID=root;Password=123456;CharSet=utf8mb4";
using (MySqlConnection connection = new MySqlConnection(connectionString))
{
connection.Open();
MySqlCommand command = new MySqlCommand("SELECT * FROM mytable", connection);
MySqlDataReader reader = command.ExecuteReader();
while (reader.Read())
{
Console.WriteLine(reader["column_name"].ToString());
}
reader.Close();
}
}
}
csharpusing MySql.Data.MySqlClient;
class Program{
static void Main(string[] args)
{
string connectionString = "Server=localhost;Database=mydb;User ID=root;Password=123456;CharSet=utf8mb4;AllowOldPasswords=true";
using (MySqlConnection connection = new MySqlConnection(connectionString))
{
connection.Open();
MySqlCommand command = new MySqlCommand("SELECT * FROM mytable", connection);
MySqlDataReader reader = command.ExecuteReader();
while (reader.Read())
{
Console.WriteLine(reader["column_name"].ToString());
}
reader.Close();
}
}
}
csharpusing MySql.Data.MySqlClient;
class Program{
static void Main(string[] args)
{
string connectionString = "Server=localhost;Database=mydb;User ID=root;Password=123456;CharSet=utf8mb4";
using (MySqlConnection connection = new MySqlConnection(connectionString))
{
connection.Open();
MySqlCommand command = new MySqlCommand("SELECT * FROM mytable", connection);
MySqlDataReader reader = command.ExecuteReader();
while (reader.Read())
{
Console.WriteLine(reader["column_name"].ToString());
}
reader.Close();
}
}
}
csharpusing MySql.Data.MySqlClient;
class Program{
static void Main(string[] args)
{
string connectionString = "Server=localhost;
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