sql - Select min group by another column -


i have table consisting of these fields:

id  |   groupid | position        ------------------------------------  ck1         10       1  ck1         10       2      ck1         10       3      ck1         11       4      ck1         11       5      ck1         11       6      ck1         12       7      ck1         12       8      ck1         12       9

i need select includes min value of position in group of registre:

id  |   groupid | position   | minposition           -------------------------------------------  ck1         10       1             1  ck1         10       2             1      ck1         10       3             1      ck1         11       4             4  ck1         11       5             4  ck1         11       6             4  ck1         12       7             7  ck1         12       8             7  ck1         12       9             7

thanks

you can use in dbms:

select id, groupid, position,  mytable mt inner join (         select id, groupid, min(position)         mytable          group id, groupid     ) mini     on mt.id = mini.id     , mt.groupid = mt.groupid

this better version if use sql server (>= 2008)

select id, groupid, position, min(position) on (partition id, groupid) mytable mt

here full code demo:

create table #temp(id char(3), groupid int, position int)  insert #temp(id, groupid, position) values (n'ck1',10,1),(n'ck1',10,2),(n'ck1',10,3),(n'ck1',11,4),(n'ck1',11,5),(n'ck1',11,6),(n'ck1',12,7),(n'ck1',12,8),(n'ck1',12,9)   select id, groupid, position, min(position) on (partition id, groupid)  minposition #temp mt  drop table #temp

this produces result:

id   groupid     position    minposition ---- ----------- ----------- ----------- ck1  10          1           1 ck1  10          2           1 ck1  10          3           1 ck1  11          4           4 ck1  11          5           4 ck1  11          6           4 ck1  12          7           7 ck1  12          8           7 ck1  12          9           7

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