/*                    /‘  `\/   `.              .   .‘      :  `. `.              \\.‘        ,  `.`  `.              `.     ,___/|\. `.   :             . \, .‘./    ‘ ‘\  ,  ‘             .\    .  \_.~ _; ;    \/‘.             `\ ..._`.   :   /..   ../              /‘ _._  \. ~ .‘   `\:            /‘.‘@   `    .---.    `.          .‘  :         ‘   @ `.\.           /   ./`.._./ ~ .      :\    `.   __       .‘   /   (        \....‘  `.  .‘ /‘  `.  /‘‘‘\   .‘    `.  /  \     :     ;‘ .‘    ..:.‘ ;   `\;       : :    :    :   .‘   :  ;    ::     `\. `\.    ;   :        \.‘     "  ‘    ; `.      `.   \ /    s    .   /       `.     .‘  `    .   `.  `\ `.     ;  /‘         ;___ ;   `.   `.  `.   `         ;          ;:__..‘     `.   `. `.     :` ‘:    _.‘    .‘ ;   :       `.     `.    .\x./-`--...../‘   ;   :         `. ..-:..-‘                  (    :           `---‘`.                     `;   :             `.  `,..                   :    :               `.    `.                  `.___;                 `.    `.                   `.    `;                     `-.,‘                 女神保佑         永无BUG*/    public static class SQLHelper    {        private static SqlConnection Con;        private static SqlCommand cmd;        private static DataTable dt;        private static DataSet ds;        private static SqlDataAdapter da;        private static string sqlstr;        private static void SQLHelper()        {            sqlstr = "";        }        /// <summary>        /// 执行一个sql语句，返回第一行第一个值        /// </summary>        /// <param name="sql"></param>        /// <returns></returns>        public static object GetFirstValue(string sql)        {            using (Con = new SqlConnection(sqlstr))            {                Con.Open();                cmd = new SqlCommand(sql, Con);                return cmd.ExecuteScalar();            }        }        /// <summary>        /// 执行一个sql语句，返回受影响行数        /// </summary>        /// <param name="sql"></param>        /// <returns></returns>        public static int GetNonQuery(string sql)        {            using (Con = new SqlConnection(sqlstr))            {                Con.Open();                cmd = new SqlCommand(sql, Con);                return cmd.ExecuteNonQuery();            }        }        /// <summary>        /// 离线模式填充datatable并返回，数据少可以用此方法        /// </summary>        /// <param name="sql"></param>        /// <returns></returns>        public static DataTable GetDataTableA(string sql)        {            using (Con = new SqlConnection(sqlstr))            {                da = new SqlDataAdapter(sql, Con);                dt = new DataTable();                da.Fill(dt);                return dt;            }        }        /// <summary>        /// 根据sql,填充datatable并返回。数据多的时候可以用此方法        /// </summary>        /// <param name="sql"></param>        /// <returns></returns>        public static DataTable GetDataTableB(string sql)        {            using (Con = new SqlConnection(sqlstr))            {                Con.Open();                cmd = new SqlCommand(sql, Con);                dt = new DataTable();                SqlDataReader reader = cmd.ExecuteReader();                dt.Load(reader);                Con.Close();                return dt;            }        }        /// <summary>        /// 传入sql语句集，返回一个dataset        /// </summary>        /// <param name="sqllist"></param>        /// <returns></returns>        public static DataSet GetDataSet(List<string> sqllist)        {            using (Con = new SqlConnection(sqlstr))            {                Con.Open();                ds = new DataSet();                foreach (string  c in sqllist)                {                    cmd = new SqlCommand(c, Con);                    dt = new DataTable();                    SqlDataReader reader = cmd.ExecuteReader();                    dt.Load(reader);                    ds.Tables.Add(dt);                }                Con.Close();                return ds;            }        }        /// <summary>        /// 在事务中执行多条sql语句        /// </summary>        /// <param name="list"></param>        /// <returns></returns>        public static bool ExecSQLSList(List<string> list)        {            using (Con = new SqlConnection(sqlstr))            {                Con.Open();                SqlTransaction tran = Con.BeginTransaction();                try                {                    foreach (string sql in list)                    {                        cmd = new SqlCommand(sql, Con);                        cmd.ExecuteNonQuery();                    }                    tran.Commit();                    Con.Close();                    return true;                }                catch                {                    tran.Rollback();                    return false;                }                finally                {                    Con.Close();                    Con.Dispose();                               }                        }                  }        /// <summary>        /// 执行一个不带参数的存储过程，返回datable        /// </summary>        /// <param name="StoredProcedureName"></param>        /// <returns></returns>        public static DataTable GetDataTableByStoredProcedure(string StoredProcedureName)        {            using (Con = new SqlConnection(sqlstr))            {                Con.Open();                cmd = new SqlCommand();                cmd.CommandText = StoredProcedureName;                cmd.CommandType = CommandType.StoredProcedure;                dt = new DataTable();                dt.Load(cmd.ExecuteReader());                return dt;            }        }    }