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MySQL: Working with coordinates in the database

How to insert coordinates in the database and how to operate with them in MySQL.

mysql

For all examples i have this two simple tables. Both tables contains 3000 rows with data:

The first table has a column ready to save the coordinate values separately, the second table will store the coordinates as POINT.

 

Save coordinates separately

 

This way we all know, we store the longitude and latitude separately with simple sql query:

To obtain data we can use a simple query like the following:

This is not anything new and interesting.

 

Store the coordinates as POINT

 

The possibility that I would like to show is save the coordinates in point form. A Point is a geometry that represents a single location in coordinate space.

Work of this type is simple. This is a simple example:

This code declare local variable in Mysql and select data from this variable. Variable is declared as POINT type, and contain coordinates.
In this case we can simple get X and Y coordinates from variable as you can see.

 

In the database we can save this variable simply as follows:

And again select values from table:

The result will look like:

ASWKT – Converts a value in internal geometry format to its WKT representation and returns the string result.
Again, we can easily access to the items saved in the coordinates with X and Y “axes”.

 

Distance between the points

In this case when we have values ​​stored as POINT, we can use the operations of this type variable. As calculate distance between two points. This is not a geometric distance, but only the distance in the polygon points.

As a result we get the distance value in units. If we calculate the distance between two points that differ by one unit, we would get a value of 1.

If we want to calculate the distance, we would have a saved value of the distance from the central point.

 

Calculation of the distance from a given point

 

If you want to calculate the distance from a certain point, we can proceed in both cases as well.

 

Coordinates are separately

Calculate the distance between two points for each row:

 

Coordinates are POINT format

As in the previous example, only approaching the coordinates through the values from POINT variable:

 

 

Create a function to calculate the distance

Pouze doporučení: V tomto případě je lepší vytvořit jednoduchou funkci v databázi.

Now we can use the same in both cases:

 

in conclusion

 

Neither way is probably better, it always depends on the use of.

Comments (6)

Thank you for this article

nabil

Very nice article.I have many gps trajectory data, it have 4 row for id, date time, lat, long. How to calculate all of data to find the distance from start and last trajectory using Haversine or other query? I don’t know to set the lat1, lat2, lon1, lo2 if the data is so big.

XW

Amazing! Its truly amazing article, I have got much clear idea regarding from this article.

Hello,Thanks for such a great informative article…But i have a question how can i get results within (lat1,long1) and (lat2,long2) so that i can get list of all the location from db …The db have id,lat,long,name,country,user_count

Regards

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