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所在平台: Udemy |
课程主页: https://www.udemy.com/course/geodjango-tutorials-by-using-postgresql-postgis-proj4-geos/
课程评论：没有评论
课程名称：使用Geodjango学习地理信息系统 课程概述： 在这门课程中，您将学习如何利用Geodjango处理地理信息，以便有效管理地理数据。课程旨在帮助您理解如何将地理位置（如经度和纬度）存储在数据库中，并通过查询实现多种功能，例如按时间顺序列出地点或根据位置筛选用户。 您将了解PointField和PolygonField数据类型的使用。PointField用于保存用户的坐标信息，而PolygonField则用于绘制特定区域，如城市、国家或建筑物的区域。课程将通过实际的例子，如使用Swarm和Tinder应用程序，教您如何查询附近的位置并按照距离排序。 通过课程，您将掌握如何设置地点查询限制，例如仅显示某一范围内的用户（如10公里内），并学会计算两个用户之间的距离。除此之外，课程还会介绍如何创建相关应用，例如社交网络应用、车辆定位应用以及房地产展示网站等。 最后，课程还会涵盖Google Maps基础知识，让您学会如何在地图上展示用户和地点，并使用HTML5地理定位功能获取经纬度信息。此外，您还将学习如何使用GEOIP库，通过IP地址获取地理位置信息（如国家、城市和地址）。 通过这门课程，您将掌握创建地理位置相关应用的技能，为今后的项目打下坚实的基础。
We can add anything onto our standard databases and then search up queries like listing them in a particular chronological order or for instance, showing people who has a name starting with the letter a. But have you ever thought about how we save a particular location, more precisely, their latitude and longitude information by using queries? What about listing these queries from the nearest to the most far, most far to the nearest and everything else like searching up within a particular kilometer? If the subject is location, we also need to learn how to use other data types as well as customary databases like pointfield or polygonfield. What is a PointField?Simply put, it is a type of data that we use to save the coordinates (latitude and longitude) of the users. What is a PolygonField?This is the type of data that you would need to use if you want to plot a particular area instead of just plotting a point on the map. Examples include: land, patch of an area, country, city, the area of a house etc.Where can I use PointField? Where would it benefit me? For example, when you check-in using the swarm app, the app will receive your latitude and logitude information where you have checked in at that moment. This information will be sent to their server and will be saved into the pointfield after being transformed into a point. Then your location will be shared with everyone instantly. What else does Swarm do? For example, when you are checking in, it comes up with some suggestions. For example, if you are eating in London in Burger King, and you have a Starbucks nearby, it will be suggested to you.Here is an example of what the suggestions may look like:Burger KingStarbucksLondonOthers....but how does swarm know that you are near these places? Because these are actually saved into the database of Swarm as a pointfield. So it's listing these localities from the closest to the most far. After you have learnt from these lectures, you will find it's really easy make such filters. Additionally, you will also learn how to add limitations within a chosen quantity of kilometer. So you could request to show people for instance only within 10km in distance and list those from the nearest to the farthest. Let's talk a bit about Tinder. What does Tinder do? It shows you the nearest opposite sex. If you are not interested in the users nearby, it will show you someone else that is farther and the distance will gradually become higher. For example, if you are not interested in the people within 0.3km away, the distance will gradually increase to like 2km, 5km, 10km but for example if you are using Tinder in Turkey, you obviously won't see people who are in Germany. Basically, Tinder saves your location into their pointfield and lists people who are the nearest to the farthest to your location. Tinder also shows your distance to other users. With these lectures, you will also learn these and how to calculate the distance in between two users using km's or miles. Congratulations, you can now create apps such as swarm, tinder or foursquare. So what else can we do? Find my friends: you can make an app where you can find all your friends over a map. You can create a special app where people can follow their girlfriends over a map. You can create an app for rent a car type of businesses to follow the location of the vehicle. For example, you can create an app for an employer who has a business that is usually done outside by an employee like working as a taxi driver. Usually, you would need an expensive GPS device for such things but you can simply make them download an app for their mobile phone and constantly watch their current location. Not only these. If you have a website about selling property (real estate) and instead of writing just the km2 of the house, you can show the location of the property on the map including its area giving more details. Who wouldn't want that? Not only all of these, after these lectures, you will also learn about all the basics of Google Maps.You will be able to show the people you have previously saved over google maps too.You will gain knowledge about map markers. You will gain knowledge about complex map markers. You will see the photos which you have taken from the database as a marker and be able to add links to them.I have learnt everything about Geodjango, learnt about the types of data, I understand Google Maps too, yes, but you talk a lot about the latitude and logitude information. Where can I find that information? This is a very smart question. If you want to do this on web, don't worry, I also talk about the usage of the html 5 geolocation feature. If you have a mobile app (objective-c for iOS and java for android) it is extremely easy to receive the latitude and longitude information. What you do with mobile applications is the same as posting the latitude and longtitude information to the server. Wow, the amount of information in the lectures are unbelievable! I think that's all we learn. No. Lastly, let's talk about GEOIP. Basically, GEOIP works by receiving the IP adress to receive information such as the country, county, city, district, adress. And yes, with these lectures, you would be able to learn how to use the GEOIP library.More info on geodjango. tumblr address.
