C# 连接MySQL
1. 添加MySQL引用
安装完MySQL之后,在安装的默认目录 C:\Program Files (x86)\MySQL\Connector NET 8.0 中查找MySQLData.dll文件。
在Visual Studio 中为项目中添加引用。
2. 引入命名空间
csharp
using MySql.Data.MySqlClient;
3. 构建连接
csharp
private static MySqlConnection m_Connect = null;
private static void Connect()
{
string connectStr = "server=127.0.0.1;port=3306;database=test;user=root;password=root;";
m_Connect = new MySqlConnection(connectStr);
}
server=IP地址;
port=端口号;
database=数据库名字;
user=管理员账号;
password=账号的密码;
4. 增删改查
增
csharp
private static void Insert()
{
try
{
m_Connect.Open();
//string sqlStr = "Insert into users(username, password) values('takil', '789')";
//string sqlStr = "Insert into users(username, password, registerdate) values('taksil', '789789', '2015-05-09')";
string sqlStr = "Insert into users(username, password, registerdate) values('wilhelm', '78889', '" + DateTime.Now + "')";
MySqlCommand cmd = new MySqlCommand(sqlStr, m_Connect);
int result = cmd.ExecuteNonQuery();
Console.WriteLine("成功影响了{0}条数据", result);
}
catch (Exception ex)
{
Console.WriteLine(ex.ToString());
}
finally
{
m_Connect?.Close();
}
}
删
csharp
private static void Delete()
{
try
{
m_Connect.Open();
string sql = "delete from users where username = 'takil'";
MySqlCommand cmd = new MySqlCommand(sql, m_Connect);
int result = cmd.ExecuteNonQuery();
Console.WriteLine("成功影响了{0}条数据", result);
}
catch (Exception ex)
{
Console.WriteLine(ex.ToString());
}
finally
{ m_Connect?.Close(); }
}
改
csharp
private static void Update()
{
try
{
m_Connect.Open();
string sql = "Update users set username = 'wqrwq', password = '123' where id = 5";
MySqlCommand cmd = new MySqlCommand( sql, m_Connect);
int result = cmd.ExecuteNonQuery();
Console.WriteLine("成功影响了{0}条数据", result);
}
catch (Exception ex)
{
Console.WriteLine(ex.ToString());
}
finally
{ m_Connect?.Close(); }
}
查
csharp
private static void Read()
{
try
{
m_Connect.Open();
string sqlStr = "select * from users";
//string sqlStr = "select id, username, registerdate from users";
MySqlCommand cmd = new MySqlCommand(sqlStr, m_Connect);
MySqlDataReader reader = cmd.ExecuteReader();
while (reader.Read())
{
//Console.WriteLine(reader[0].ToString() + " " + reader[1].ToString() + " " + reader[2].ToString());
//Console.WriteLine(reader.GetInt32(0) + " " + reader.GetString(1) + " " + reader.GetString(2));
Console.WriteLine(reader.GetInt32("id") + " " + reader.GetString("username") + " " + reader.GetString("password"));
}
}
catch(Exception ex)
{
Console.WriteLine(ex.ToString());
}
finally
{
m_Connect?.Close();
}
}
csharp
private static void ReadCount()
{
try
{
m_Connect.Open();
string sqlStr = "select Count(*) from users";
MySqlCommand cmd = new MySqlCommand(sqlStr, m_Connect);
//MySqlDataReader reader = cmd.ExecuteReader();
//reader.Read();
//int count = Convert.ToInt32(reader[0]);
//Console.WriteLine("总数为{0}", count);
object result = cmd.ExecuteScalar();
int count = Convert.ToInt32(result);
Console.WriteLine("总数为{0}", count);
}
catch (Exception ex)
{
Console.WriteLine(ex.ToString());
}
finally
{ m_Connect?.Close(); }
}
验证
csharp
private static bool ValifyUser(string username, string password)
{
try
{
m_Connect.Open();
//string sqlStr = "select * from users where username = '" + username + "' and password = '" + password + "'";
string sqlStr = "select * from users where username = @para1 and password = @para2";
MySqlCommand cmd = new MySqlCommand(sqlStr, m_Connect);
cmd.Parameters.AddWithValue("para1", username);
cmd.Parameters.AddWithValue("para2", password);
MySqlDataReader reader = cmd.ExecuteReader();
if(reader.Read())
{
return true;
}
}
catch (Exception ex)
{
Console.WriteLine(ex.ToString());
}
finally
{
m_Connect?.Close();
}
return false;
}
因为作者精力有限,文章中难免出现一些错漏,敬请广大专家和网友批评、指正。