[Index(nameof(FirstName), nameof(LastName))]publicclassPerson{publicintPersonId {get;set; }publicstringFirstName {get;set; }publicstringLastName {get;set; } } Indexes over multiple columns, also known ascomposite indexes, speed up queries which filter on index's columns, but also queries wh...
[Index(nameof(FirstName), nameof(LastName))] public class Person { public int PersonId { get; set; } public string FirstName { get; set; } public string LastName { get; set; } } Indexes over multiple columns, also known as composite indexes, speed up queries which filter on index'...
使用EF Core 移轉 自訂資料模型在本節中,您會了解到如何使用指定格式、驗證和資料庫對應規則的屬性來自訂資料模型。 然後在下列幾個章節中,您會透過將屬性新增到您已建立的類別,以及為模型中剩餘的實體類型建立新的類別,來建立完整的 School 資料模型。
数据库列的值可以通过多种方式生成:主键列通常是自动递增的整数,其他列具有默认值或计算值等。本页详细介绍使用 EF Core 配置值生成的各种模式。 默认值 在关系数据库中,可以为列配置默认值;如果插入的行没有该列的值,则将使用默认值。 可以在属性上配置默认值: ...
Observed - EF Core mapper doesn't support multiple columns with same name even if they belong to different tables. It was working with Entity framework. Method in EF Core code where it fails public static int[] BuildIndexMap([CanBeNull] IReadOnlyList<string> columnNames, [NotNull] DbData...
By default, EF Core will map to tables and columns named exactly after your .NET classes and properties. For example, mapping a typical Customer class to PostgreSQL will result in SQL such as the following: CREATETABLE"Customers" ("Id"integerNOT NULLGENERATED BY DEFAULTASIDENTITY,"FullName"tex...
While your code will use the Samurai.SecretIdentity type and navigate through that to the First and Last properties, those two properties will resolve as columns in the Samurais database table. EF Core convention will name them with the name of the property in Samurai (SecretIdentity) and the...
EF7 allows the default conventions used by EF Core to be removed. For example, it usually makes sense to create indexes for foreign key (FK) columns, and hence there is a built-in convention for this: ForeignKeyIndexConvention. However, indexes add overhead when updating rows, and it may...
Just as we used a SQL EXISTS subquery to translate the LINQ Contains operator, EF now allows you to use arbitrary LINQ operators over such primitive collection columns – just as if they were regular DbSets; in other words, primitive collections are now fully queryable. For example, to find...
The table columns that participate in the foreign key constraint are specified in an Association element. The Association element that corresponds to a given AssociationSet element is specified in the Association attribute of the AssociationSet element....