C# sqlLite连接数据库

【实例截图】

【核心代码】

 public class HelpSQLlite 
    {
        private SQLiteConnection conn = null;
        private SQLiteCommand cmd = null;
        private SQLiteDataReader sdr = null;

        /// <summary>
        /// 构造函数
        /// </summary>
        public HelpSQLlite()
        {
            conn = new SQLiteConnection(@"Data Source =G:\LeiShenDB.db; Pooling = true");
        }

        /// <summary>
        /// 获取连接结果，未连接打开连接
        /// 连接结果
        /// </summary>
        /// <returns></returns>        
        private SQLiteConnection GetConn()
        {
            if (conn.State == ConnectionState.Closed)
            {
                conn.Open();
            }
            return conn;
        }

        /// 该方法执行传入的增删改SQL语句
        /// 要执行的增删改SQL语句
        /// 返回更新的记录数
        public int ExecuteNonQuery(string sql)
        {
            int res;
            try
            {
                cmd = new SQLiteCommand(sql, GetConn());
                res = cmd.ExecuteNonQuery();
            }
            catch (Exception ex)
            {
                res = -1;
                throw ex;
            }
            finally
            {
                if (conn.State == ConnectionState.Open)
                {
                    conn.Close();
                }
            }
            return res;
        }

        /// 执行带参数的SQL增删改语句
        /// SQL增删改语句
        /// 参数集合
        /// 返回更新的记录数
        public int ExecuteNonQuery(string sql, SQLiteParameter[] paras)
        {
            int res;
            using (cmd = new SQLiteCommand(sql, GetConn()))
            {
                cmd.Parameters.AddRange(paras);
                res = cmd.ExecuteNonQuery();
            }
            return res;
        }

        /// 该方法执行传入的SQL查询语句
        /// SQL查询语句
        /// 返回数据集合
        public DataTable ExecuteQuery(string sql)
        {
            DataTable dt = new DataTable();
            cmd = new SQLiteCommand(sql, GetConn());
            using (sdr = cmd.ExecuteReader(CommandBehavior.CloseConnection))
            {
                dt.Load(sdr);
            }
            return dt;
        }




        /// 执行带参数的SQL查询语句
        /// SQL查询语句
        /// 参数集合
        /// 返回数据集合
        public DataTable ExecuteQuery(string sql, SQLiteParameter[] paras)
        {
            DataTable dt = new DataTable();
            cmd = new SQLiteCommand(sql, GetConn());
            cmd.Parameters.AddRange(paras);
            using (sdr = cmd.ExecuteReader(CommandBehavior.CloseConnection))
            {
                dt.Load(sdr);
            }
            return dt;
        }

        /// 执行带参数的SQL查询判断语句
        /// SQL查询语句
        /// 参数集合
        /// 返回是否为空
        public bool BoolExecuteQuery(string sql, SQLiteParameter[] paras)
        {
            DataTable dt = new DataTable();
            cmd = new SQLiteCommand(sql, GetConn());
            cmd.Parameters.AddRange(paras);
            try
            {
                using (sdr = cmd.ExecuteReader(CommandBehavior.CloseConnection))
                {
                    dt.Load(sdr);
                }
            }
            catch (Exception e)
            {
                throw e;
            }
            DataRow[] rows = dt.Select();
            bool temp = false;
            if (rows.Length > 0)
            {
                temp = true;
            }
            return temp;
        }


        /// 该方法执行传入的SQL查询判断语句
        /// SQL查询语句
        /// 返回是否为空
        public bool BoolExecuteQuery(string sql)
        {
            DataTable dt = new DataTable();
            cmd = new SQLiteCommand(sql, GetConn());
            using (sdr = cmd.ExecuteReader(CommandBehavior.CloseConnection))
            {
                dt.Load(sdr);
            }
            DataRow[] rows = dt.Select();
            bool temp = false;
            if (rows.Length > 0)
            {
                temp = true;
            }
            return temp;
        }

    }