操作Sql数据库帮助类

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data.SqlClient;
using System.Data;

namespace DateBase
{
    public class Helper
    {
        /// <summary>
        /// 定义SqlConnection
        /// </summary>
        public static SqlConnection conn = null;

        /// <summary>
        /// 数据库连接 public static string str = ConfigurationManager.AppSettings["MySqlConncetion"];
        /// </summary>
        public static string str = "Data Source=.;Initial Catalog=MyOffice;User ID=www_jy;password=*****************";

        /// <summary>
        /// 事物回滚
        /// </summary>
        public static SqlTransaction trans = null;

        /// <summary>
        /// 打开数据库连接
        /// </summary>
        public static SqlConnection Connection
        {
            get
            {
                try
                {
                    if (conn == null)
                    {
                        conn = new SqlConnection(str);
                        conn.Open();
                    }
                    else if (conn.State == ConnectionState.Closed)
                    {
                        conn.Open();
                    }
                    else if (conn.State == ConnectionState.Broken)
                    {
                        conn.Close();
                        conn.Open();
                    }
                }
                catch (Exception e)
                {
                    //抛出错误
                }

                return conn;
            }
        }

        /// <summary>
        /// 打开事物
        /// </summary>
        public static void OpenTrans()
        {
            try
            {
                trans = Connection.BeginTransaction();
            }
            catch (Exception e)
            {
                //抛出异常
            }
        }

        /// <summary>
        /// 事物提交
        /// </summary>
        public static void CommitTrans()
        {
            trans.Commit();
        }

        /// <summary>
        /// 事物回滚
        /// </summary>
        public static void RollBackTrans()
        {
            trans.Rollback();
        }

        /// <summary>
        /// 执行增、删、改
        /// </summary>
        /// <param name="sql"></param>
        /// <returns></returns>
        public static int GetExecute(string sql)
        {
            int num = 0;
            try
            {
                SqlCommand cmd = new SqlCommand(sql, Connection);
                cmd.Transaction = trans;
                num = cmd.ExecuteNonQuery();
            }
            catch (Exception e)
            {
                //抛出异常
                RollBackTrans();
            }
            finally
            {
                //关闭数据库连接
                conn.Close();
            }
            return num;
        }

        /// <summary>
        /// 有参数执行增、删、改操作
        /// </summary>
        /// <param name="sql"></param>
        /// <param name="pare"></param>
        /// <returns></returns>
        public static int GetExecute(string sql, SqlParameter[] pare)
        {
            int num = 0;
            try
            {
                SqlCommand cmd = new SqlCommand(sql, Connection);
                cmd.Parameters.AddRange(pare);
                cmd.Transaction = trans;
                num = cmd.ExecuteNonQuery();
            }
            catch (Exception e)
            {
                //抛出异常
                RollBackTrans();
            }
            finally
            {
                //关闭数据库连接
                conn.Close();
            }
            return num;
        }

        /// <summary>
        /// 查询条数
        /// </summary>
        /// <param name="sql"></param>
        /// <returns></returns>
        public static int GetExecuteScalar(string sql)
        {
            int num = 0;
            try
            {
                SqlCommand cmd = new SqlCommand(sql, Connection);
                num = Convert.ToInt32(cmd.ExecuteScalar());
            }
            catch (Exception e)
            {
                //抛出异常
            }
            finally
            {
                //关闭数据库连接
                conn.Close();
            }
            return num;
        }

        /// <summary>
        /// 条件查询
        /// </summary>
        /// <param name="sql"></param>
        /// <param name="pare"></param>
        /// <returns></returns>
        public static int GetExecuteScalar(string sql, SqlParameter[] pare)
        {
            int num = 0;
            try
            {
                SqlCommand cmd = new SqlCommand(sql, Connection);
                cmd.Parameters.AddRange(pare);
                num = Convert.ToInt32(cmd.ExecuteScalar());
            }
            catch (Exception e)
            {
                //抛出异常
            }
            finally
            {
                //关闭数据库连接
                conn.Close();
            }
            return num;
        }

        /// <summary>
        /// 查找数据库
        /// </summary>
        /// <param name="sql"></param>
        /// <returns></returns>
        public static DataSet GetDataSet(string sql)
        {
            DataSet ds = new DataSet();
            try
            {
                SqlDataAdapter adapter = new SqlDataAdapter(sql, Connection);
                adapter.Fill(ds);
            }
            catch (Exception e)
            {
                //抛出异常
            }
            finally
            {
                //关闭数据库连接
                conn.Close();
            }
            return ds;
        }

        /// <summary>
        /// 有参查找数据库
        /// </summary>
        /// <param name="sql"></param>
        /// <param name="pare"></param>
        /// <returns></returns>
        public static DataSet GetDataSet(string sql, SqlParameter[] pare)
        {
            DataSet ds = new DataSet();
            try
            {
                SqlCommand cmd = new SqlCommand(sql, Connection);
                cmd.Parameters.AddRange(pare);
                SqlDataAdapter adapter = new SqlDataAdapter(cmd);
                adapter.Fill(ds);
            }
            catch (Exception e)
            {
                //抛出异常
            }
            finally
            {
                //关闭数据库连接
                conn.Close();
            }
            return ds;
        }
    }
}