sql - Finding the min distance MYSQL -

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i want find min distance between (x2-x1)^2 + (y2-y1)^2 particular macid , timestamp. i'm trying find nearest possible gate location individual @ 1 particular instance of time. so, query should return 1 unique value of user @ 1 instance of time min gate location.

the data set looks like:

   x1       y1    timestamp    macid               x2    y2      gate | 5618  | 5303 |1 12:22:02 | 54:ea:a8:53:5b:eb | 5844  | 5377  | c24 | 5848  | 5046 |1 12:22:02 | 54:ea:a8:53:5b:eb | 5844  | 5377  | c18 | 6094  | 5464 |1 12:22:02 | 54:ea:a8:53:5b:eb | 5844  | 5377  | c17 | 6021  | 6540 |1 13:09:48 | 48:5a:3f:6a:01:b9 | 6210  | 6801  | c23 | 6366  | 7036 |1 13:09:48 | 48:5a:3f:6a:01:b9 | 6210  | 6801  | c14 | 6366  | 7036 |1 13:09:48 | 48:5a:3f:6a:01:b9 | 6210  | 6801  | c13

the result set should below:

   x1       y1    timestamp    macid               x2    y2      gate | 5848  | 5046 |1 12:22:02 | 54:ea:a8:53:5b:eb | 5844  | 5377  | c18 | 6021  | 6540 |1 13:09:48 | 48:5a:3f:6a:01:b9 | 6210  | 6801  | c23

i have tried below query not working:

select min((x2-x1)^2 + (y2-y1)^2), macid, timestamp maptable  groupbymacid, timestamp

i tried using self joins seems wrong.

may know i'm going wrong.

you use query:

select m.* maptable m, (   select timestamp, macid, min(pow((x2-x1), 2) + pow((y2-y1), 2)) mindist   maptable   group timestamp, macid ) m.timestamp = a.timestamp , m.macid = a.macid  , pow((x2-x1), 2) + pow((y2-y1), 2) = a.mindist;

sql fiddle: http://sqlfiddle.com/#!9/d7979/6

but note not return 1 row per macid , date, because in input data 2 final rows same, min distance same gates c13 , c14


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