System.Data.Entity Assembly: EntityFramework.dll An implementation of IDatabaseInitializer that will recreate and optionally re-seed the database only if the database does not exist. To seed the database, create a derived class and override the Seed method. ...
CreateDatabaseIfNotExists:顾名思义,如果数据库不存在则新建数据库 DropCreateDatabaseAlways:无论数据库是否存在,始终重建数据库 DropCreateDatabaseIfModelChanges:仅当领域模型发生变化时才重建数据库 在实际应用当中,我们可以直接使用以上数据库初始化策略,在调用Database对象的Initialize方法时,Entity Framework就会根据...
You’ll learn how Code First conventions select a database and how you can alter this convention or specify the exact database that your context should use. The topics we cover will help you target other database providers, deploy your application, and perform many other database-related tasks...
Entity Framework 6.2.0 Search System.ComponentModel.DataAnnotations System.ComponentModel.DataAnnotations.Schema System.Data.Entity System.Data.Entity CreateDatabaseIfNotExists<TContext> Database DbConfiguration DbConfigurationTypeAttribute DbContext DbContextTransaction DbFunctionAttribute DbFunctions DbModelBuilder...
Entity Framework 6.2.0 Search System.ComponentModel.DataAnnotations System.ComponentModel.DataAnnotations.Schema System.Data.Entity System.Data.Entity CreateDatabaseIfNotExists<TContext> Database DbConfiguration DbConfigurationTypeAttribute DbContext DbContextTransaction DbFunctionAttribute DbFunctions DbModelBuilder...
context.Database.Exists()) { // if database did not exist before - create it context.Database.Create(); } else { // query to check if MigrationHistory table is present in the database var migrationHistoryTableExists = ((IObjectContextAdapter)context)...
The TPH strategy requires that database columns be nullable for any property not defined in the root type of the hierarchy, even if that property is required. It is possible to create a database constraint for these columns to ensure the value is non-null whenever an instance with that prop...
Create the databaseUpdate Program.cs to create the database if it doesn't exist:Visual Studio Visual Studio Code C# Copy using ContosoUniversity.Data; using Microsoft.EntityFrameworkCore; var builder = WebApplication.CreateBuilder(args); builder.Services.AddRazorPages(); builder.Services.AddDb...
REQUIRES: using EntityFramework.Utilities; PROVIDER DEPENDENT: This methods uses raw sql to drop connections so only works against sql server Drops the mssql database even if it has connections open. Solves the problem when you are recreating the database in your tests and Management Studio has...
The Entity Framework bridges this gap between the models using a mapping layer. Thus there are three layers active in the Entity Framework’s model: Conceptual layer Mapping layer Logical layer These three layers allow data to be mapped from a relational database to a more object-orien...