sql - MySql UPDATE statement with SELECT summarizing data from table 2 -

i have 2 tables, table has columns token (primary key) , downtime (int), table b has columns token, status (enum 3 states: active, unstable, inactive), duration (int).

i want sum duration table b, states unstable , inactive. , after that, assign result column downtime, table a.

so, example,

table =======  token             downtime --------------------------  bv87pxicnrtk8pw       null v3525kq2kzihb9u       null  table b ======= token                 state       duration ------------------------------------------ v3525kq2kzihb9u      active              9 v3525kq2kzihb9u    unstable             20 v3525kq2kzihb9u    inactive             60 bv87pxicnrtk8pw    unstable             11 bv87pxicnrtk8pw      active            140 bv87pxicnrtk8pw    inactive             40  result ====== token             downtime --------------------------  bv87pxicnrtk8pw         51 v3525kq2kzihb9u         80 

i tried

update set downtime = (select sum(duration) b state != 'active' group token) a.token = b.token; 

but without success.

newbie in sql. can me?

in mysql can use join , update as

update tablea join(   select    token,sum(duration) duration tableb   state != 'active'   group token )b on b.token = a.token set a.downtime = b.duration