entity-framework

问题 model.cs [Column(TypeName = "json")] public string application_role { get; set; } Its MySQL, data type of particular column is json , and how to add it in a model class. I tried with DataAnnotations but getting error as The specified type member 'application_role' is not supported in LINQ to Entities. Only initializers, entity members, and entity navigation properties are supported. Linq Query to get data context.sc_employee_details .Where(e => e.user_name.Equals(userName)) .Select(o => o

问题 model.cs [Column(TypeName = "json")] public string application_role { get; set; } Its MySQL, data type of particular column is json , and how to add it in a model class. I tried with DataAnnotations but getting error as The specified type member 'application_role' is not supported in LINQ to Entities. Only initializers, entity members, and entity navigation properties are supported. Linq Query to get data context.sc_employee_details .Where(e => e.user_name.Equals(userName)) .Select(o => o

问题 I've looked the question up but nothing I have found is working for me. I created a view in SQL which works when you run it in the Management Studio. When the view is accessed from my MVC Application, EF is returning identical rows instead of rows with different data. Table: Cars [Id] [Registration] [Make] [Model] Table: Bookings [Id] [BookingStartDate] [BookingEndDate] [CarId] View: CarBookings SELECT [C].[Id], [C].[Registration], [C].[Make], [C].[Model], [B].[BookingStartDate], [B].

问题 I'm trying to achieve something in EF Core that worked very well for me in EF 6. I'm serializing the contents of a List<T> property as a Json string in the DB. <T> can be pretty much anything, since Json.Net takes care of serializing whatever we throw at it. My collection exposes a Json string property and takes care of serializing/deserializing itself. This approach is convenient and efficient for structured nested data where a relational model would bring needless overhead and complexity.

问题 I'm trying to achieve something in EF Core that worked very well for me in EF 6. I'm serializing the contents of a List<T> property as a Json string in the DB. <T> can be pretty much anything, since Json.Net takes care of serializing whatever we throw at it. My collection exposes a Json string property and takes care of serializing/deserializing itself. This approach is convenient and efficient for structured nested data where a relational model would bring needless overhead and complexity.

问题 I'm not sure I understand what exactly IQueryable is. I understand that it doesn't get me all the entities and puts the constraint part in memory but executes it as part of the command it sends to the database. Please correct me if I'm mistaken and tell me, why should my repository functions return IQueryable and not a simple List ? 回答1: An IQueryable is not actually a collection of entities, rather it describes how to obtain that collection. The data is never retrieved from the source until

问题 The bounty expires in 3 days . Answers to this question are eligible for a +50 reputation bounty. Kirsten Greed wants to reward an existing answer : Reward this answer and draw attention to stackoverflow.com/questions/65753462/… We are getting eventually an IndexOutOfRange exception when running code like this: result.Data = dbOptima.Database.ExecuteStoredProcedure( task, StoredProcedureValues.PROC_GET_TASKS).ToList(); ,where ExecuteStoredProcedure does the following: public static

问题 The bounty expires in 3 days . Answers to this question are eligible for a +50 reputation bounty. Kirsten Greed wants to reward an existing answer : Reward this answer and draw attention to stackoverflow.com/questions/65753462/… We are getting eventually an IndexOutOfRange exception when running code like this: result.Data = dbOptima.Database.ExecuteStoredProcedure( task, StoredProcedureValues.PROC_GET_TASKS).ToList(); ,where ExecuteStoredProcedure does the following: public static

问题 In my Asp.Net MVC 5 project I use Entity Framework code first to work with MS SQL database. Suppose this is the table: public class Ticket { [Key] public int Id { get; set; } [Required] public string ReferenceCode { get; set; } //Rest of the table } In this table, whenever I add a new code I want the ReferenceCode column to be a unique and random AlphaNumeric (containing only letters and digits) string with a specific length. This will allow users to refer to a specific ticket for instance.

问题 Closed. This question is not reproducible or was caused by typos. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 2 months ago . Improve this question I'm following one of Mosh Hamedani Course on ASP.NET MVC in Udemy. I came across one error while designing my Database using code-first (Entity Framework). At first, I got the error of " No DbContext was found in assembly" . After resolving this problem