[RUBY] [In team development] Error when moving to another member's branch and doing rails s [Rails]

Reference target person

--Team development beginner --People who are having trouble with database-related errors when developing apps with Rails --Git beginner

environment

$ rails -v
Rails 6.0.3.1

$ ruby -v
ruby 2.7.0p0 (2019-12-25 revision 647ee6f091) [x86_64-darwin19]

$ git --version
git version 2.27.0

$ mysql --version
mysql  Ver 14.14 Distrib 5.7.29, for osx10.15 (x86_64) using  EditLine wrapper

Status

--I wanted to move to another member's branch and check the behavior for review, but I got an error when starting the server. ――It seems that there is a database-related error.

ActiveRecord::PendingMigrationError

https://qiita.com/KONTA2019/items/0444ae3b8c8936a56ee0

Refer to the above and solve the problem. By the way, I

$ rails db:migrate

Solved with.

But after that, I got the following error. .. ..

Multiple migrations have the name ~~~.

In conclusion, ~~~ will contain ** migration file name **.

In the case of I,

Multiple migrations have the name CreateUsers.

And when I check my migration file,

$ rails db:migrate:status

 Status   Migration ID    Migration Name
--------------------------------------------------
   up     20200618162841  Create tweetposts
   up     20200620004226  Change tweetposts to tweets
  down    20200621075518  Create posts
  down    20200623102444  Change posts to chats
  down    20200627042358  Create users
   up     20200627080839  Create users
   up     20200627083356  Add column to users
  down    20200627220915  Change datatype content of chats
   up     20200703201452  ********** NO FILE **********
  down    20200710035709  Add user id to tweets

There was a CreateUsers file.

I think you can guess it well, but from the content of the error statement, it is presumed that "** There is a migration file with the same name, so I do not know which one to refer to when building the database **". I can do it.

So down 20200627042358 Create users Delete this file and

$ rails db:migrate
$ bundle exec rails s

You have now started the server!

By the way, ...

Of the migration file up 20200703201452 ********** no file **********

You're curious, right? ??

This is a mysterious phenomenon that the database is built with reference to the missing files, so I would like to delete it.

The cause of this is that the migration file was deleted before the migration was down, but the solution is as follows.

https://qiita.com/beanbeenzou/items/e8886071ab1e1cf7a9c0