How do you fix to change the identity property of a column the column needs to be dropped and recreated?
How do you fix to change the identity property of a column the column needs to be dropped and recreated?
System. InvalidOperationException: To change the IDENTITY property of a column, the column needs to be dropped and recreated….I had to:
- Comment the table totally from code.
- Run a migration that clears it from DB.
- Uncomment table again with corrected mapping.
- Run migration again.
Which Fluent API method that can be used to configure a default value for the column that the property maps to?
Fluent API HasDefaultValue method
The Entity Framework Core Fluent API HasDefaultValue method is used to specify the default value for a database column mapped to a property.
How do you change identity column to non identity?
If you need to keep the data, but remove the IDENTITY column, you will need to:
- Create a new column.
- Transfer the data from the existing IDENTITY column to the new column.
- Drop the existing IDENTITY column.
- Rename the new column to the original column name.
Is OnModelCreating required?
OnModelCreating is not necessary, but at the same time will not hurt if called – that’s why Sometimes it’s there, sometimes not. Sometimes at the beginning of the method, other times at the end.
What is ModelBuilder in EF core?
The ModelBuilder is the class which is responsible for building the Model. The ModelBuilder builds the initial model from the entity classes that have DbSet Property in the context class, that we derive from the DbContext class. It then uses the conventions to create primary keys, Foreign keys, relationships etc.
What is Databasegenerated DatabaseGeneratedOption none )]?
DatabaseGeneratedOption. None option specifies that the value of a property will not be generated by the underlying database. This will be useful to override the default convention for the id properties.
Which framework is better than Entity Framework?
With EF you can focus more on a domain first approach since the data layer is completely abstracted for you.
How to setup Entity Framework?
From the Visual Studio menu,select Tools > NuGet Package Manager > Package Manager Console
What is Entity Framework and benefit of Entity Framework?
With the Entity Framework, developers can work at a higher level of abstraction when they deal with data, and can create and maintain data-oriented applications with less code compared with traditional applications.
What are some alternatives to Entity Framework?
No indexes or bad indexes. Spend time desiging a good indexing strategy.