Code First Migrations - Package Manager Console Host Version 5.9.1.0

Joann Liao 21 Reputation points
2021-04-18T20:35:35.577+00:00

Need your expertise. Please advise.

There's old table which already released to Production. It's already migrated and had related 2 recorded on the list of migrations ~IRM.SIMSDB\Migrations.

In recent, we want to make four changes on this table. including

  1. A column, A decimal type field, it needs to be changed its decimal points from 2 to 4
  2. B column B field needs to be removed from the table
  3. C column C field needs to be rename its name to C2 from C1
  4. Add a new column D as decimal type

all other data fields should stay the same.

So, please advise a best solution to migration this old table. e.g. Add-migration and Update-Database or make code change at Configuration set AutomaticMigrationsEnabled = true or something else.

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3 answers

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  1. Daniel Zhang-MSFT 9,611 Reputation points
    2021-04-19T02:32:24.74+00:00

    Hi JoannLiao-4647,
    I suggest you use existing schema as a starting point.
    First create an initial blank migration, then you can add migrations for any new changes.
    Run the Add-Migration InitialCreate –IgnoreChanges command in Package Manager Console. This creates an empty migration with the current model as a snapshot.
    More details you can refer to this document.
    Best Regards,
    Daniel Zhang

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  2. Joann Liao 21 Reputation points
    2021-04-19T20:52:15.457+00:00

    DuaneArnold-0443,

    I do have administrator role on Database. If U use DBA tools to do the migration, I am much concerns any possible confliction or violation at CODE-FIRST base the application to Start up?

  3. Joann Liao 21 Reputation points
    2021-04-20T17:35:40.303+00:00

    DuaneArnold-0443

    I am hands-on programming on SQL for many years. Last week, I did manually changed on SQL to manipulating the data field to be with decimal digit number from 2 to 5. I was wondering whether this approach is OK? Whether this kind of manual change via SQL , it may cause confliction with EF migration or not.