网上很少dbhelper的基于mysql数据库的，所以实现了下mysql的dbhelper，封装好了各种方法调用数据库函数，可以应用于小型的c#程序中。使用时记得修改password和端口号，mysql默认是3306，我自己定义了新端口号，所以是3307。
using System;using System.Collections.Generic;using System.Text;using System.Data;using MySql.Data.MySqlClient;namespace studentdb{ public class DBHelper { //引导数据库连接数据库调用Web.Config文件 private static MySqlConnection connection; //创建连接 public static MySqlConnection Connection { get { MySqlConnection myConn = new MySqlConnection("Database=student;Data Source=localhost;User Id=root;Password=pw;pooling=false;CharSet=gb2312;port=3307"); string connectionString = myConn.ConnectionString; if (connection == null) { connection = new MySqlConnection(connectionString); //打开连接 connection.Open(); } else if (connection.State == System.Data.ConnectionState.Closed) { connection.Open(); } else if (connection.State == System.Data.ConnectionState.Broken) { connection.Close(); connection.Open(); } return connection; } } //（无参）返回执行的行数(删除修改更新) public static int ExecuteCommand(string safeSql) { MySqlCommand cmd = new MySqlCommand(safeSql, Connection); int result = cmd.ExecuteNonQuery(); return result; } //（有参） public static int ExecuteCommand(string sql, params MySqlParameter[] values) { MySqlCommand cmd = new MySqlCommand(sql, Connection); cmd.Parameters.AddRange(values); return cmd.ExecuteNonQuery(); } //（无参）返回第一行第一列(删除修改更新) public static int GetScalar(string safeSql) { MySqlCommand cmd = new MySqlCommand(safeSql, Connection); int result = Convert.ToInt32(cmd.ExecuteScalar()); return result; } //（有参） public static int GetScalar(string sql, params MySqlParameter[] values) { MySqlCommand cmd = new MySqlCommand(sql, Connection); cmd.Parameters.AddRange(values); int result = Convert.ToInt32(cmd.ExecuteScalar()); return result; } //返回一个DataReader（查询） public static MySqlDataReader GetReader(string safeSql) { MySqlCommand cmd = new MySqlCommand(safeSql, Connection); MySqlDataReader reader = cmd.ExecuteReader(); return reader; } public static MySqlDataReader GetReader(string sql, params MySqlParameter[] values) { MySqlCommand cmd = new MySqlCommand(sql, Connection); cmd.Parameters.AddRange(values); MySqlDataReader reader = cmd.ExecuteReader(); return reader; } //返回一个DataTable public static DataTable GetDataSet(string safeSql) { DataSet ds = new DataSet(); MySqlCommand cmd = new MySqlCommand(safeSql, Connection); MySqlDataAdapter da = new MySqlDataAdapter(cmd); da.Fill(ds); return ds.Tables[0]; } public static MySqlDataAdapter GetAdapter(string safeSql) { DataSet ds = new DataSet(); MySqlCommand cmd = new MySqlCommand(safeSql, Connection); //cmd.Parameters.AddRange(values); MySqlDataAdapter da = new MySqlDataAdapter(cmd); return da; } public static DataTable GetDataSet(string sql, params MySqlParameter[] values) { DataSet ds = new DataSet(); MySqlCommand cmd = new MySqlCommand(sql, Connection); cmd.Parameters.AddRange(values); MySqlDataAdapter da = new MySqlDataAdapter(cmd); da.Fill(ds); return ds.Tables[0]; } }}
