SQLAlchemy中有一个upsert-esque操作：
db.session.merge()
找到此命令后，我可以执行upsert，但是值得一提的是，对于批量“ upsert”而言，此操作很慢。
另一种方法是获取您要向上插入的主键的列表，并在数据库中查询任何匹配的ID：
# Imagine that post1, post5, and post1000 are posts objects with ids 1, 5 and 1000 respectively# The goal is to "upsert" these posts.# we initialize a dict which maps id to the post objectmy_new_posts = {1: post1, 5: post5, 1000: post1000}for each in posts.query.filter(posts.id.in_(my_new_posts.keys())).all(): # only merge those posts which already exist in the database db.session.merge(my_new_posts.pop(each.id))# only add those posts which did not exist in the database db.session.add_all(my_new_posts.values())# Now we commit our modifications (merges) and inserts (adds) to the database!db.session.commit()
