Hi,

a solution you might do using completely SSIS data flow component should be like that :

add a data flow task

in the data flow task add an ole db source for your table A

connect it to a lookup task

in the lookup task configure it to match your table B on your keys field

in the lookup you have three output possible :

Match , no match and error if you ve configured it.

connect the no match to an oleb destination (table b)

connect the match to an execute ole db task for your update.

that's all.