我如何确定宇宙DB容器是空的并且需要播种？

Question

我通过EF核心访问我的宇宙数据库数据库。

我可以通过EF Core Overriden进行启用，以检查基础数据库和容器是否存在。但是我不确定如何检查它是否包含任何数据？

EFCORE似乎没有任何计数，或者无法检查基础数据库是空的吗？

这是我到目前为止

  protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        var client = Database.GetCosmosClient();
        var dbResponse = client.CreateDatabaseIfNotExistsAsync("Db").Result.StatusCode;
        ContainerProperties containerProperties = new ContainerProperties("forms", "/forms");
        var database = client.GetDatabase("Db");
        var containerResponse = database.CreateContainerIfNotExistsAsync(containerProperties).Result.StatusCode;

        //Database or container was recently created, hence reseed 
        if (dbResponse == System.Net.HttpStatusCode.Created
            || containerResponse == System.Net.HttpStatusCode.Created)
        {
            Console.WriteLine("Model created but need seeding");
    return;
        }

        var container = database.GetContainer("forms");
    //How to check data is in the container?            

    }

根据@SvyAtoslav Danyli提供的答案来尝试的，我创建了两种方法。

using Microsoft.EntityFrameworkCore;
using System.Linq;

namespace FormsRetriever
{
    public static class SeedingTools
    {
        public static void CheckDatabase(DbContext dbContext)
        {
            dbContext.Database.EnsureCreated();
            var client = dbContext.Database.GetCosmosClient();
            SeedData(dbContext);

        }

        private static void SeedData(DbContext dbContext)
        {

            bool a = dbContext.Set<Forms>().Any();
        }
    }
}

我打电话给初创公司。

作为回报给我这个错误

A host error has occurred during startup operation '50913447-b407-41a1-95bd-68918f9d3d4b'.
[2022-07-04T11:04:53.059Z] Microsoft.EntityFrameworkCore: The LINQ expression 'DbSet<Forms>()
[2022-07-04T11:04:53.059Z]     .Any()' could not be translated. Either rewrite the query in a form that can be translated, or switch to client evaluation explicitly by inserting a call to 'AsEnumerable', 'AsAsyncEnumerable', 'ToList', or 'ToListAsync'. See https://go.microsoft.com/fwlink/?linkid=2101038 for more information.

Answer 1

将检查代码移至适当的功能并在正确配置EF Core时执行：

public static class DatabaseTools
{
    public static void CheckDatabase(DbContext context)
    {
        // EF Core will create database and containters
        context.Database.EnsureCreated();

        // Cosmos provider do not supports Any
        if (dbContext.Set<Form>().FirstOrDefault() == null)
        {
            // seed data
            context.Set<Form>().AddRange(
                new []
                {
                    new Form{},
                    new Form{},
                    new Form{},
                }
            );

            context.SaveChanges();
        }
    }
}