dotnet6 entity framework where clause

Question

i have converted by project from dotnet core 2.1 to dotnet 6. i am in the process of converting it step by step. the thing which i am stuck now is where clause. i am not able to run this simple query in repository

  public IQueryable<PostType> getPostType()
    {
       
    

        var d= _context.PostType.Where(e => e.PostStatusId==2).ToList();  // this thing is not working
        return _context.PostType.Where(e => e.PostStatusId == 2);
    }

anyone can get why? queries are working before

this is the result

Posttype

CREATE TABLE [dbo].[PostType](
[PostTypeId] [int] NOT NULL,
[PostTypeGuid] [uniqueidentifier] NULL,
[ParentId] [int] NULL,
[CategoryId] [int] NULL,
[Name] [varchar](100) NOT NULL,
[Slug] [varchar](500) NULL,
[ThumbnailImg] [nvarchar](255) NULL,
[WebSiteId] [int] NULL,
[PostStatusId] [int] NOT NULL,
[isMediaType] [bit] NOT NULL,
[isNewsletter] [bit] NOT NULL,
[AllowableExtension] [varchar](100) NULL,
[CreatedBy] [int] NULL,
[CreatedDate] [datetime] NULL,
[ModifiedBy] [int] NULL,
[ModifiedDate] [datetime] NULL,
 CONSTRAINT [PK_PostType] PRIMARY KEY CLUSTERED 
(
    [PostTypeId] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, FILLFACTOR = 80) ON [PRIMARY]
) ON [PRIMARY]
GO

ALTER TABLE [dbo].[PostType] ADD  CONSTRAINT [DF_PostType_PostTypeGuid]  DEFAULT (newid()) FOR [PostTypeGuid]
GO

ALTER TABLE [dbo].[PostType] ADD  CONSTRAINT [DF_PostType_int_PostStatusId]  DEFAULT ((2)) FOR [PostStatusId]
GO

"is not working" is not very helpful. How is it not working? Exception? Returns empty result? — Guru Stron
– Guru Stron, Commented Nov 17, 2022 at 14:06
Show us the definition of class PostType , and show us your CREATE TABLE statements. — Dai
– Dai, Commented Nov 17, 2022 at 14:10

Guru Stron · Accepted Answer · 2022-11-17 14:21:54Z

2

I would argue that this issue is similar to this one and caused by addition of nullable reference types and their support in EF Core. See the Required and optional properties -> Conventions section of the docs:

C# 8 introduced a new feature called nullable reference types (NRT), which allows reference types to be annotated, indicating whether it is valid for them to contain null or not. This feature is enabled by default in new project templates, but remains disabled in existing projects unless explicitly opted into. Nullable reference types affect EF Core's behavior in the following way:

If nullable reference types are disabled, all properties with .NET reference types are configured as optional by convention (for example, string).

If nullable reference types are enabled, properties will be configured based on the C# nullability of their .NET type: string? will be configured as optional, but string will be configured as required.

Either disable nullable reference types for the project or mark corresponding properties as nullable (in this case some string causes the issue, so change string to string? for corresponding properties).

answered Nov 17, 2022 at 14:21

Guru Stron

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11 Comments

jmcilhinney Over a year ago

It looks like Slug, ThumbnailImg and AllowableExtension all need to be changed from string to string? if nullable reference types are not disabled.

Guru Stron Over a year ago

@jmcilhinney yes

maztt Over a year ago

it doesn't work by changing these three properties. corresponding foreign tables are linked needed to be changed as well?

Guru Stron Over a year ago

@maztt exception changes or is the same?

maztt Over a year ago

it works by disabling

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