Exam 70-487 topic 1 question 75 discussion

Actual exam question from Microsoft's 70-487

Question #: 75
Topic #: 1

You are developing an ASP.NET Core web application by using an Entity Framework code-first approach. The application uses an Azure SQL Database. The code-first migration is configured to run as part of a continuous integration build.
You must add an Azure MySQL Database. This database must use the same schema as the existing Azure SQL Database instance.
You need to configure the migration to ensure that the existing TFS build definition remains unchanged.
What are two possible ways to achieve this goal? Each correct answer presents a complete solution.
Each correct selection is worth one point.
NOTE:

A. Use the ActiveProvider property to specify the provider to which the migration is applied.
B. Create a new type that derives from DbContext and override the ActiveProvider object. Then, add or apply migrations using this type.
C. Use the Entity Framework Core Fluent API to identify database providers.
D. Create a separate Migration Assembly than the one containing the DbContext and switch the active provider during build.

Show Suggested Answer

Suggested Answer: BC 🗳️
References:
https://medium.com/@rc_dos_santos/how-configure-asp-net-core-web-api-project-with-mysql-database-b7a64a247a99

by seanlim at Nov. 21, 2019, 10:44 a.m.

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Dreamchaser1980

Highly Voted 4 years, 9 months ago

I thinks It’s A & B. D is wrong in this case because the TFS build definition remains unchanged. The answer specifies that the active provider would change during the build. A: https://docs.microsoft.com/en-us/ef/core/managing-schemas/migrations/providers#one-migration-set “If operations can only be applied on one provider (or they’re differently between providers), use the ActiveProvider property to tell which provider is active.” B: https://docs.microsoft.com/en-us/ef/core/managing-schemas/migrations/providers#two-migration-sets “Another approach that makes working with the tools easier is to create a new type that derives from your DbContext and overrides the active provider. This type is used at design time when adding or applying migrations.”

upvoted 6 times

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bashirmja

Most Recent 4 years, 5 months ago

A&D is correct. https://vceguide.com/what-are-two-possible-ways-to-achieve-this-goal-94/

upvoted 2 times

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mmk1991

5 years, 3 months ago

https://docs.microsoft.com/en-us/ef/core/managing-schemas/migrations/providers?tabs=dotnet-core-cli

upvoted 4 times

exgam_20

5 years, 1 month ago

If you read this properly, the correct answers are B and D

upvoted 12 times

Natali

5 years ago

You need to configure the migration to ensure that the existing TFS build definition remains unchanged. how do you switch provider during build knowing that?

upvoted 2 times

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GabF

5 years ago

I agree with exgam_20. If you open the link from mmk1991 (https://docs.microsoft.com/en-us/ef/core/managing-schemas/migrations/providers?tabs=dotnet-core-cli) you will find: "Two migration sets (Option D) In the first approach, you generate two migrations for each model change. One way to do this is to put each migration set in a separate assembly and manually switch the active provider (and migrations assembly) between adding the two migrations. (Option B) Another approach that makes working with the tools easier is to create a new type that derives from your DbContext and overrides the active provider. This type is used at design time when adding or applying migrations."

upvoted 4 times

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seanlim

5 years, 7 months ago

https://medium.com/@balramchavan/setup-entity-framework-core-for-mysql-in-asp-net-core-2-5b40a5a3af94

upvoted 1 times

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