php sql help. adding rows together??

[jcrensha627]

Im trying to figure out how to add rows together to get "volume"

 

here an example of my table

 

id symbol shares volume price

13 JAME 100 100 50.00

14 JAME 50 "X" 50.00

 

what SQL query do i use to make the "x" in id 14 equal to the volume in 13 + shares in 14.

 

basically how do i have "X" replaced with 150

[sasa]

UPDATE table_name a, table_name b
SET b.volume = a.volume + b. shares
WHERE a.id='13' AND b.id='14'

[jcrensha627]

Thanks SASA, do you know how i can have this work all id's not just specific ones.

[RussellReal]

remove the wheres lol