C#连接SQLServer数据库

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

using System.Data;
using System.Data.Sql;
using System.Data.SqlClient;

//这个是连接数据库用的类

namespace SQLConnectWindows
{
    class sqlhelper
    {
        //数据库名称
        public  string sourceName = "UQVYNFZSKG81DQB";
        //用户名称
        public  string userName = "sa";
        //用户密码
        public  string pwd = "123456";
        //连接的数据库名称
        public  string database = "zd_tcTwo";
        //连接数据库
        SqlConnection conn;
        //执行操作
        DataSet dataSet = new DataSet();
        
        public DataSet MySQLConnect(string sql)
        {
            //连接数据库
            string connstr = "data source=" + sourceName + ";user=" + userName + ";pwd=" + pwd + ";database=" + database;
            conn = new SqlConnection(connstr);

            try
            {
                //打开数据库连接
                conn.Open();

                //执行sql命令
                SqlCommand cmd = new SqlCommand(sql, conn);


                //适配命令通道
                SqlDataAdapter adapter = new SqlDataAdapter(cmd);
                
                //命令执行
                adapter.Fill(dataSet);

                //清除参数
                cmd.Parameters.Clear();
                
            }
            catch (Exception e)
            {
                Console.Write(e.Message);
            }
            finally {
                //关闭数据库连接
                conn.Close();
            }
            return dataSet;
        }
    }
}

执行SQL语句：在方法中调用

//可以存在于其他类中
private void button1_Click(object sender, EventArgs e)
        {
            try {
                string cmd = "INSERT INTO [dbo].[userInfo]([uid],[uname],[umid])VALUES('" + 1 + "','" + 1 + "','" + 1 + "')";
                sqlhelper.MySQLConnect(cmd);
            }
            catch (DataException data) {
                Console.Write(data.Message);
            }
        }