I always forget the syntax for these statements in MSSQL because I don't use them enough...

Insert:

INSERT INTO table_a (id, name)
  SELECT id, name
  FROM table_b LEFT JOIN table_c ON table_b.id = table_c.b_id

Update:

UPDATE table_a
SET table_a.assid = table_b.assid
FROM table_a
    INNER JOIN table_b ON table_a.id = table_b.a_id

Delete:

DELETE table_a
FROM table_a
    LEFT JOIN table_b ON table_b.id = table_a.b_id