c# java同理 连接数据库获取某张表内容数量

参考文章参考

class db
        {
            private SQLiteConnection dbConnection;
            //private SQLiteCommand cd;
            //private SQLiteDataReader read;

            public SQLiteConnection lian(string path)
            {
                //创建连接字符串
                try
                {
                    string databaseFileName = path;
                    string connectionString = "data source = " + databaseFileName;
                    //链接数据库
                    dbConnection = new SQLiteConnection(connectionString);
                    dbConnection.Open();
                }
                catch (Exception e)
                {
                    Console.Write(e + "对象");
                }
                return dbConnection;
            }

        }
db b= new db();
             //创建连接字符串
            string path="C:/QQ.db";
string count;
                string sqlc = "select count(*) as num from '" + str + "';";
                //加载sql
                SQLiteCommand cdsc = new SQLiteCommand(sqlc, b.lian(path));
                //执行
                SQLiteDataReader drc = cdsc.ExecuteReader();
                if (drc.Read()) {
                    count = drc["num"].ToString();
                    Console.Write(count);
                }