- #Ef 6 commands how to#
- #Ef 6 commands update#
We've removed the plural name and changed it lower case. We edit the OnModelCreating method in our BookStoreContext class: protected override void OnModelCreating(ModelBuilder modelBuilder) However, if you ever do need to write some custom SQL, this can make things easier. This is also not something you need to do because the majority of your data access will be done using Entity Framework. We’ll change the names of our tables and columns to contain only lowercase letters and underscores. SELECT * FROM users is the same as SELECT * FROM Users, but is not the same as SELECT * FROM "Users". This is because PostgreSQL converts all names to lowercase when used in a SQL statement.ĬREATE TABLE users (userid integer) is the same as CREATE TABLE Users (UserId integer) You can name your tables and columns using mixed case characters, but you will need to write your SQL using double quotes. This is not something you need to do, but it is a good idea to use consistent plurals, or don’t use them at all.Ĭase sensitivity can sometimes be a problem when working with PostgreSQL. We don’t want to pluralise any of our table names. We'll override some of the configuration via Fluent API in the OnModelCreating() method.
#Ef 6 commands update#
It is safe to do so because we've not used it to update our database yet.
We can run this command now to remove our initial migration. Remove-Migration will remove the last migration class. There are a few things we want to change.
Using the default configurations does not create a suitable database schema for our use case. This will apply all the migrations which haven't been run against your database. Once you're happy with the migrations (or SQL script), you can run the command Update-Database. With Script-Migration you want to make sure the SQL script will do exactly what you want it to do when you run Update-Database. Nullable types are nullable columns in the database. You'll also spot which columns in the tables are allowed to be left empty ( NULL).
There is a DELETE RESTRICT referential action on both of our foreign key clauses. An index is also created for each foreign key column. This on the N side of the 0/1:N relationship. A foreign key column is created in our Books table called AuthorId, and in our Review table called BookId. We could have named our property BookID, which would have created a column called BookID Public virtual ICollection Books Id are primary keys with auto-increment values. Inside a new folder - we'll call it Model - add the following classes: // Model/Author.cs We need to create our classes for our entities. We're starting with an empty ASP.NET Core Web project. Our example will allow us to cover a range of techniques for customising our database schema. We'll have books with metadata such as title and price. Project Setup using Visual Studio Project Example This post will help you see what's possible when using EF Core Migrations. However, you'll see below that we can overcome this by using the SQL method in MigrationBuilder, which will allow us to run any SQL statement. One criticism of using Entity Framework Migrations is that the default conventions doesn't support all SQL statements when creating your database. However, while writing this post we found this: DBUpĭBUp is worth investigating if you prefer or want to consider using SQL first. We design our entity classes according to the needs of the business and keep our database in sync using EF Core Migrations.Īnother issue we encountered when using SQL first was remembering which scripts we had ran against our database. You then update your entity classes manually.Įntity Framework Core Migrations is all about keeping your database in sync with your application. One of the issues we had with SQL first was keeping our database schema in sync with our application.Īny changes you need to perform on your existing database is done by creating a new SQL script. SQL (database) first means writing SQL scripts to create your database and creating your context and entity classes from your existing database. SQL (Database) First vs EF Core Migrations Use the SQL method in MigrationBuilder to run any SQL statement. To use Fluent API to override EF Core's default conventions. To forward engineer (code first) - where the database is created from the entity classes - using Npgsql. An alternative to using Entity Framework Core Migrations. You'll be shown ways to write your own migration steps missing in Entity Framework Core. Plus, sometimes it's not enough to use EF Core's predefined migrations to create a valid database schema. For example, changing the table and column names to help handle quoted names in PostgreSQL queries. We'll override Entity Framework's default conventions to improve our database schema. #Ef 6 commands how to#
You'll be shown how to write classes, which we will use to create our database schema.
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