sql server 2012 - How do I update a value in SQL by looking up another table using that value? -

i have table superkittens column name 'kittenid'

this value number, such 12345.

i have table called kittens 2 columns, kittenid , kittennewid

i want update superkittens , change kittenid kittennewid, using table kittens values.

i thought might work, apparently it's not valid:

update superkittens sk  set sk.kittenid =  (select kittennewid kittens k k.kittenid = sk.kittenid)

any ideas?

edit: error got it's invalid sql:

msg 102, level 15, state 1, line 1 incorrect syntax near 'sk'.

you may try this:

update superkittens sk  set sk.kittenid = k.kittennewid kittens k inner join  on sk.kittenid = k.kittenid

or may try merge option this:

merge superkittens sk     using kittens k       on sk.kittenid = k.kittenid  when matched    update        set sk.kittenid = k.kittennewid;

O9