


Use coordinates to search for buildings within a specified radius
When processing geographic data, you usually need to find objects within a certain range of a specific location. This is particularly useful for tasks such as finding buildings within a certain radius of a specific point. In this article, we'll focus on finding all buildings within 5 miles of a given set of coordinates.
Data structure
Our database table is named "Building" and contains the following necessary information:
- name: building name
- lat: latitude coordinate
- lng: longitude coordinates
Challenge
We want to retrieve all buildings that fall within a 5 mile radius of a specific point, which we will represent using a given set of coordinates:
- -84.38653999999998 (longitude)
- 33.72024 (latitude)
Initial attempt
To search for buildings within the desired range, we might initially consider using the ST_Contains function. However, this approach only works if we store the coordinates as a single geometry. Since we are using separate latitude and longitude columns, ST_Contains cannot be applied directly.
Solution
Instead, we can leverage two other functions to perform point-based geospatial calculations: ST_DWithin and ST_Distance. Let's explore them individually.
1. ST_DWithin
ST_DWithin allows us to check if a geometry is within a specified distance of another geometry. Here's an example of how we use it in this situation:
SELECT name, long, lat, ST_Distance('POINT(-84.38653999999998, 33.72024)'::geography, ST_MakePoint(long, lat)) * 0.000621371 AS distance FROM building WHERE ST_DWithin('POINT(-84.38653999999998, 33.72024)'::geography, ST_MakePoint(long, lat), 8046.72); -- 8046.72 米 = 5 英里
2. ST_Distance
ST_Distance Calculates the distance (in meters) between two geometries. We can use this to find all buildings within 5 miles and then convert the distance to miles:
SELECT name, long, lat, ST_Distance('POINT(-84.38653999999998, 33.72024)'::geography, ST_MakePoint(long, lat)) * 0.000621371 AS distance FROM building WHERE ST_Distance('POINT(-84.38653999999998, 33.72024)'::geography, ST_MakePoint(long, lat)) * 0.000621371 < 5;
Note that the order of arguments is critical when constructing ST_Point geometries. The first parameter represents longitude and the second parameter represents latitude.
When executing either of these two queries, you should get the results you want: a list of building names, longitude, latitude and distance from the specified coordinates, filtered to include only those buildings within a 5 mile radius .
The above is the detailed content of How to Find Buildings Within a 5-Mile Radius Using Latitude and Longitude Coordinates?. For more information, please follow other related articles on the PHP Chinese website!

This article explores optimizing MySQL memory usage in Docker. It discusses monitoring techniques (Docker stats, Performance Schema, external tools) and configuration strategies. These include Docker memory limits, swapping, and cgroups, alongside

This article addresses MySQL's "unable to open shared library" error. The issue stems from MySQL's inability to locate necessary shared libraries (.so/.dll files). Solutions involve verifying library installation via the system's package m

The article discusses using MySQL's ALTER TABLE statement to modify tables, including adding/dropping columns, renaming tables/columns, and changing column data types.

This article compares installing MySQL on Linux directly versus using Podman containers, with/without phpMyAdmin. It details installation steps for each method, emphasizing Podman's advantages in isolation, portability, and reproducibility, but also

This article provides a comprehensive overview of SQLite, a self-contained, serverless relational database. It details SQLite's advantages (simplicity, portability, ease of use) and disadvantages (concurrency limitations, scalability challenges). C

This guide demonstrates installing and managing multiple MySQL versions on macOS using Homebrew. It emphasizes using Homebrew to isolate installations, preventing conflicts. The article details installation, starting/stopping services, and best pra

Article discusses configuring SSL/TLS encryption for MySQL, including certificate generation and verification. Main issue is using self-signed certificates' security implications.[Character count: 159]

Article discusses popular MySQL GUI tools like MySQL Workbench and phpMyAdmin, comparing their features and suitability for beginners and advanced users.[159 characters]


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

AI Hentai Generator
Generate AI Hentai for free.

Hot Article

Hot Tools

WebStorm Mac version
Useful JavaScript development tools

MinGW - Minimalist GNU for Windows
This project is in the process of being migrated to osdn.net/projects/mingw, you can continue to follow us there. MinGW: A native Windows port of the GNU Compiler Collection (GCC), freely distributable import libraries and header files for building native Windows applications; includes extensions to the MSVC runtime to support C99 functionality. All MinGW software can run on 64-bit Windows platforms.

Dreamweaver CS6
Visual web development tools

Atom editor mac version download
The most popular open source editor

SublimeText3 English version
Recommended: Win version, supports code prompts!
