有哪些ORM:EF Core、Dapper、SqlSugar、FreeSql等 EF Core 与其他 ORM 比较(EF Core、Dapper) Entity Framework Core(EF Core)是 Microsoft 官方的ORM框架。优点:功能强大、官方支持、生产效率高、力求屏蔽底层数据库差异;缺点:复杂、上手门槛高、不熟悉EF Core的话可能会掉坑。 Dapper 优点:简单,N分钟即可上手,行...
EF Core会自动识别。 一对多关系数据的获取 代码语言:javascript 复制 Article a=ctx.Articles.Include(a=>a.Comments).Single(a=>a.Id==1);//生成的是left joinConsole.WriteLine(a.Title);foreach(Comment cina.Comments){Console.WriteLine(c.Id+":"+c.Message);}// 通过Comments查询Article也是相同的写法...
This worked fine until moving from EF core 5 to EF core 6. With EF core 6 the result list contains some null values (which should not be the case because the where condition asks for not null). Is there some breaking change / limitation in EF core 6 I'm not aware of or is this...
context.Database.ExecuteSqlCommand("UPDATE YourTable SET YourColumn = 'NewValue' WHERE YourCondition"); 这将执行指定的 SQL 命令,但不会返回任何结果。
This feature is being introduced in EF Core 7.0. In most databases, each column covered by an index can be either ascending or descending. For indexes covering only one column, this typically does not matter: the database can traverse the index in reverse order as needed. However, for compo...
var singleValue = await context.Database.ExecuteScalarAsync<int?>("SELECT SomeColumn FROM YourTable WHERE Id = @p0", new SqlParameter("p0", someId)); } 1. 2. 3. 4. 5. 但是请注意,ExecuteScalarAsync方法不是EF Core的一部分;在EF Core中,您可能需要使用FromSqlRaw或FromSqlInterpolated与Select...
timeOnly.AddHours(value)DATEADD(hour, , @value@timeOnly)EF Core 8.0 timeOnly.AddMinutes(value)DATEADD(minute, , @value@timeOnly)EF Core 8.0 timeOnly.HoursDATEPART(hour, @timeOnly)EF Core 8.0 timeOnly.IsBetween(start, end)@timeOnly>= @start AND @timeOnly<@endEF Core 8.0 ...
Before EF Core 3.0, the same entity instance would be used for every occurrence of an entity with a given type and ID. This matches the behavior of tracking queries. For example, this query:C# Copy var results = context.Products.Include(e => e.Category).AsNoTracking().ToList(); ...
var data = dbContext.YourEntities .Include(x => x.RelatedEntity) .Where(x => x.SomeCondition) .ToList(); 参考链接 EF Core Query Splitting Behavior EF Core Performance Considerations 通过以上方法,可以有效解决QuerySplittingBehavior.SingleQuery警告问题,提升应用程序的性能。
When the collection selector has a where clause, which references the outer element, then EF Core translates it to a database join and uses the predicate as the join condition. Normally this case arises when using collection navigation on the outer element as the collection selector. If the ...