将PHP函数添加到MySQL查询中

Question

I have 2 questions from this query.

$query = mysql_query($con, "SELECT id, ".calcDistance($mLat, $mLng, ."lat"., ."lng".)." as distnc FROM users WHERE fName LIKE '%".$search."%' OR lName LIKE '%".$search."%' ORDER BY distnc");

Now before I go on with the questions let me explain my variables and functions.

calcDistance() is a function that returns the distance from 2 latitudes and longitude, actually latitude and longitude of the logged in user and another user. And the parameters passed are the logged in user latitude, logged in user longitude, second user latitude and second user longitude.

$mLat is a variable for the logged in user latitude

$mLng is a variable for the logged in user longitude

lat and lng are column names in the MySQL database table called users.

Now my main aim is to show searched result ordering the result by the nearest user with the search word. Which is the reason I am using the calcDistance() function in the query.

FIRST QUESTION

When I run this query, I get a Parse error: syntax error, unexpected '.'. I don't know why I am getting this error.

SECOND QUESTION

I tried passing numbers directly as the parameters so as to stop the error I get from the 1st question. But I still get another error Warning: mysqli_fetch_array() expects parameter 1 to be mysqli_result, boolean given.

My aim is to order a user search according to the nearest user. Using the calcDistance() returns the distance between the logged in user and another user like I said.

The lat and lng columns are columns where each user latitude and longitude are saved

Answer 1

And after some research, I go my answer for here https://gist.github.com/statickidz/8a2f0ce3bca9badbf34970b958ef8479

METHOD 1

This should roughly sort the items on distance in MySQL, and should work in SQLite. If you need to sort them preciser, you could try using the Pythagorean theorem (a^2 + b^2 = c^2) to get the exact distance.

SELECT * FROM table ORDER BY ((lat-$user_lat)*(lat-$user_lat)) + ((lng - $user_lng)*(lng - $user_lng)) ASC

METHOD 2

SELECT id, (6371 * acos (cos ( radians($user_lat) )* cos(radians( lat ) ) * cos( radians( lng ) - radians($user_lng)) + sin ( radians($user_lat) ) * sin( radians( lat ) ))) AS distance FROM table HAVING distance < 30 ORDER BY distance LIMIT 0 , 20;