TSQL: UPDATE with INSERT INTO SELECT FROM

Question

so I have an old database that I\'m migrating to a new one. The new one has a slightly different but mostly-compatible schema. Additionally, I want to renumber all tables from

Answer 1

Probably the simplest way would be to add a column on MV6.Posts for oldId, then insert all the records from the old table into the new table. Last, update the old table matching on oldId in the new table with something like:

UPDATE mv5.posts
SET newid = n.id
FROM mv5.posts o, mv6.posts n 
WHERE o.id = n.oldid

You could clean up and drop the oldId column afterwards if you wanted to.