Resolved EF Core - 8 DbContext.Add does not insert non-key fields ?

[gpranjan]

The following code gives an exception
"Microsoft.Data.SqlClient.SqlException : Cannot insert the value NULL into column 'last_update_time', table 'asubio1-db.dbo.expt_table'; column does not allow nulls. INSERT fails."

Appears to be nothing wrong with the code below

namespace expt;

using NUnit.Framework;

using Microsoft.EntityFrameworkCore;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;

[Table("expt_table")]
public class DbPageCompleted {

    [Column("user_name")]
    [MaxLength(50)]
    [Required]
    [Key]
    public string? userName {get; set;}

    [Column("last_update_time")]
    [Required]
    public DateTime? lastUpdateTime;
}

public class ExptContext : DbContext {


    public DbSet<DbPageCompleted> pageCompletions { get; set; }

    protected string connectionStr()
    {
        var connStr = Environment.GetEnvironmentVariable("SQLCONNSTR_DbConn");
        if (connStr == null) throw new NoDbConnection();
        return connStr;
    }

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        string? connStr = connectionStr();
        optionsBuilder.UseSqlServer(connStr);
    }

    public static ExptContext dbContext = new ExptContext();
}

[TestFixture]
public class ExptTests {


    DbPageCompleted dbPageCompleted = new DbPageCompleted {
        userName = "[EMAIL]test@localhost.com[/EMAIL]",
        lastUpdateTime = DateTime.Now.ToUniversalTime()
    };

    [Test]
    public void Expt() {
        ExptContext dbContext = ExptContext.dbContext;
        dbContext.pageCompletions.Add(dbPageCompleted);
        dbContext.SaveChanges();
    }
}

and the project file is

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <TargetFramework>net8.0</TargetFramework>
    <ImplicitUsings>enable</ImplicitUsings>
    <Nullable>enable</Nullable>

    <IsPackable>false</IsPackable>
    <IsTestProject>true</IsTestProject>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.5.0" />
    <PackageReference Include="NUnit" Version="3.13.3" />
    <PackageReference Include="NUnit3TestAdapter" Version="4.4.2" />
    <PackageReference Include="NUnit.Analyzers" Version="3.6.1" />
    <PackageReference Include="coverlet.collector" Version="3.2.0" />
  </ItemGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.EntityFrameworkCore" Version="8.0.0" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="8.0.0" />
  </ItemGroup>
</Project>

 

[Skydiver]

Thanks for trying to put your code in MarkDown code tags, but unfortunately this site only supports BBCODE. I've put your code into BBCODE code tags.

 

[gpranjan]

I found the answer, by trial and error, plus hints from others

It turns out that all fields of the DB class need to be properties

    [Column("last_update_time")]
    [Required]
    public DateTime? lastUpdateTime;

should be

    [Column("last_update_time")]
    [Required]
    public DateTime? lastUpdateTime {get; set; }