CODEWITHSUNDEEP
database-migrationfluent-migrator
DanilGholtsman
DanilGholtsman

Reputation: 2374

New migration without erasing old data

We're using FluentMigrator in one project. Let's say I got code like this one below.

So every time when we run new migration all the previous data deleting. Is there are way to avoid it and keep safe the data in places which are not changing?

  public class Migration1 : Migration
    {
        public override void Up() {
            Create.Table("Project")
                .WithColumn("id").AsInt64().PrimaryKey().Identity()
                .WithColumn("name").AsString(30).Nullable()
                .WithColumn("author").AsString(30).Nullable()
                .WithColumn("date").AsDate().Nullable()
                .WithColumn("description").AsString(1000).Nullable();

            Create.Table("Data")
                .WithColumn("id").AsInt64().PrimaryKey().Identity()
                .WithColumn("project_id").AsInt64().ForeignKey("Project", "id")
                .WithColumn("a").AsInt32().Nullable()
                .WithColumn("b").AsInt32().Nullable()
                .WithColumn("c").AsInt32().Nullable()
                .WithColumn("d").AsInt32().Nullable();
        }

        public override void Down() {
            Delete.Table("data");
            Delete.Table("project");
        }
    }

Upvotes: 0

Views: 127

Answers (1)

Castrohenge
Castrohenge

Reputation: 8983

As part of you Down method you could create some backup tables which are identical to the table you are deleting but are post fixed with a timestamp. Eg:

Project_201407091059
Data_201407091059

You could then copy all the data from the tables being deleted to these tables.

Upvotes: 1

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