MySQL update all values in column based on max date and group -


i'm trying use group clause update dt column based on column 'last'. need find last date group 'group hid,tid,tdate,fid,did,depid,acc' , set 'dt' value record in group.

for example:

|       id |   hid | tid |      tdate | fid | did |    p2 | depid |  acc |   dt |                 last | |----------|-------|-----|------------|-----|-----|-------|-------|------|------|----------------------| |  3742030 | 12332 |   1 | 2017-09-02 |   1 |   1 |  9560 |     1 | 5334 |    1 | 2016-11-03t09:00:20z | |  3799297 |  2386 |   1 | 2017-08-29 |   1 |   1 |  8480 |     1 | 5352 |    1 | 2016-11-03t11:12:55z | |  4848877 |  2386 |   1 | 2017-08-29 |   1 |   1 |  8720 |     1 | 5352 | 2369 | 2016-12-17t16:59:22z | | 10706343 | 12332 |   1 | 2017-09-02 |   1 |   1 |  9660 |     1 | 5334 | 2065 | 2017-03-01t12:32:27z | | 14546682 |  2386 |   1 | 2017-08-29 |   1 |   1 | 11720 |     1 | 5352 | 4431 | 2017-05-12t10:24:09z | | 15824920 | 12332 |   1 | 2017-09-02 |   1 |   1 | 10820 |     1 | 5334 | 1111 | 2017-07-15t05:19:04z |

to

|       id |   hid | tid |      tdate | fid | did |    p2 | depid |  acc |   dt |                 last | |----------|-------|-----|------------|-----|-----|-------|-------|------|------|----------------------| |  3742030 | 12332 |   1 | 2017-09-02 |   1 |   1 |  9560 |     1 | 5334 | 1111 | 2016-11-03t09:00:20z | |  3799297 |  2386 |   1 | 2017-08-29 |   1 |   1 |  8480 |     1 | 5352 | 4431 | 2016-11-03t11:12:55z | |  4848877 |  2386 |   1 | 2017-08-29 |   1 |   1 |  8720 |     1 | 5352 | 4431 | 2016-12-17t16:59:22z | | 10706343 | 12332 |   1 | 2017-09-02 |   1 |   1 |  9660 |     1 | 5334 | 1111 | 2017-03-01t12:32:27z | | 14546682 |  2386 |   1 | 2017-08-29 |   1 |   1 | 11720 |     1 | 5352 | 4431 | 2017-05-12t10:24:09z | | 15824920 | 12332 |   1 | 2017-09-02 |   1 |   1 | 10820 |     1 | 5334 | 1111 | 2017-07-15t05:19:04z |

schema: http://sqlfiddle.com/#!9/4fad1d/1

is there way update rows in table based on group?

thanks

join table subquery find recent row per group.

update of t join (   select t1.*   of t1   join (     select hid,tid,tdate,fid,did,depid,acc, max(last) last     of     group hid,tid,tdate,fid,did,depid,acc   ) t2 using (hid,tid,tdate,fid,did,depid,acc,last) ) t3 using (hid,tid,tdate,fid,did,depid,acc) set t.dt = t3.dt;

http://sqlfiddle.com/#!9/93708/2

for join in subquery can use natural join

  natural join (     select hid,tid,tdate,fid,did,depid,acc, max(last) last     of     group hid,tid,tdate,fid,did,depid,acc   ) t2

http://sqlfiddle.com/#!9/e7e5ee/1


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