无主键的 EF Core

问题描述 投票：0回答：1

我知道许多其他人也问过有关没有主键的 EF Core 的类似问题，但我没有找到解决以下问题的方法。

如果我使用原始 SQL 命令，它可以工作：

using Confluent.Kafka;
using Microsoft.EntityFrameworkCore;
using System.Text.Json;
using System.Text.Json.Nodes;

string connectionString = "Server=localhost; Database=pubs; User ID=***; Password=***; TrustServerCertificate=True;";
string bootstrapServers = "localhost:9092";
string topicName = "cbsource";

var consumerConfig = new ConsumerConfig
{
    BootstrapServers = bootstrapServers,
    GroupId = "CB_SQL_consumer_EF_Core",
    AutoOffsetReset = AutoOffsetReset.Earliest
};

var cancellationTokenSource = new CancellationTokenSource();
Console.CancelKeyPress += (_, e) =>
{
    e.Cancel = true;
    cancellationTokenSource.Cancel();
};

try
{
    using (var consumer = new ConsumerBuilder<Ignore, string>(consumerConfig).Build())
    {
        consumer.Subscribe(topicName);

        var dbContext = new PubDbContext(connectionString);

        while (!cancellationTokenSource.Token.IsCancellationRequested)
        {
            try
            {
                var consumeResult = consumer.Consume(cancellationTokenSource.Token);

                if (consumeResult.Message.Value != null) 
                {
                    Console.WriteLine($"Consumed message: {consumeResult.Message.Value}");

                    JsonObject? jsonObject = JsonSerializer.Deserialize<JsonObject>(consumeResult.Message.Value);

                    if (jsonObject != null)
                    {
                        int? outerTableColumn1Value = null;
                        string? outerTableColumn2Value = null;
                        int? innerTableColumn1Value = null;
                        string? innerTableColumn2Value = null;

                        outerTableColumn1Value = int.TryParse(jsonObject["outer1"]?.ToString(), out int parsedNumber)
                            ? parsedNumber : null;

                        outerTableColumn2Value = jsonObject["outer2"]?.ToString();

                        var inner1Value = jsonObject["inner"]?["inner1"]?.ToString();
                        var inner2Value = jsonObject["inner"]?["inner2"]?.ToString();

                        if (!string.IsNullOrEmpty(inner1Value) || !string.IsNullOrEmpty(inner2Value))
                        {
                            innerTableColumn1Value = int.TryParse(inner1Value, out parsedNumber)
                                ? parsedNumber : null;

                            innerTableColumn2Value = inner2Value;
                            Console.WriteLine("Inner table exists.");
                        }
                        else
                        {
                            Console.WriteLine("Inner table does not exist.");
                        }

                        var transaction = dbContext.Database.BeginTransaction();

                        try
                        {
                            string sqlCommand = @"SELECT TOP 1 * FROM OuterTable WHERE Outer1 = {0}";
                            string updateCommand = "";
                            string insertCommand = "";

                            var outerEntity = await dbContext.OuterTable
                                .FromSqlRaw(sqlCommand, outerTableColumn1Value)
                                .FirstOrDefaultAsync();

                            if (outerEntity != null)
                            {
                                updateCommand = @"UPDATE OuterTable SET Outer2 = {1} WHERE Outer1 = {0}";

                                #pragma warning disable CS8604

                                await dbContext.Database.ExecuteSqlRawAsync(updateCommand,
                                    outerTableColumn1Value, outerTableColumn2Value);

                                #pragma warning restore CS8604

                                Console.WriteLine("Outer table row updated.");
                            }
                            else
                            {
                                insertCommand = @"INSERT INTO OuterTable (Outer1, Outer2) VALUES ({0}, {1})";

                                #pragma warning disable CS8604

                                await dbContext.Database.ExecuteSqlRawAsync(insertCommand,
                                outerTableColumn1Value, outerTableColumn2Value);

                                #pragma warning restore CS8604

                                Console.WriteLine("Outer table row inserted.");
                            }

                            sqlCommand = @"SELECT TOP 1 * FROM InnerTable WHERE Inner1 = {0}";

                            var innerEntity = await dbContext.InnerTable
                                .FromSqlRaw(sqlCommand, innerTableColumn1Value)
                                .FirstOrDefaultAsync();

                            if (innerEntity != null)
                            {
                                updateCommand = @"UPDATE InnerTable SET Inner2 = {1} WHERE Inner1 = {0}";

                                #pragma warning disable CS8604

                                await dbContext.Database.ExecuteSqlRawAsync(updateCommand,
                                    innerTableColumn1Value, innerTableColumn2Value);

                                #pragma warning restore CS8604

                                Console.WriteLine("Inner table row updated.");
                            }
                            else
                            {
                                insertCommand = @"INSERT INTO InnerTable (Inner1, Inner2) VALUES ({0}, {1})";

                                #pragma warning disable CS8604

                                await dbContext.Database.ExecuteSqlRawAsync(insertCommand,
                                    innerTableColumn1Value, innerTableColumn2Value);

                                #pragma warning restore CS8604

                                Console.WriteLine("Inner table row inserted.");
                            }
                        
                            await transaction.CommitAsync();
                        }
                        catch (Exception ex)
                        {
                            await transaction.RollbackAsync();

                            Console.WriteLine($"Error: {ex.Message}. Transaction rolled back.");
                        }
                    }
                }
            }

            catch (ConsumeException e)
            {
                Console.WriteLine($"Error during consume: {e.Error.Reason}");
            }
        }
    }
}
catch (OperationCanceledException)
{
    Console.WriteLine("Consumer has been cancelled.");
}

public class PubDbContext : DbContext
{
    private readonly string _connectionString;

    public PubDbContext(string connectionString)
    {
        _connectionString = connectionString;
    }

    public DbSet<OuterTable> OuterTable { get; set; }
    public DbSet<InnerTable> InnerTable { get; set; }

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        optionsBuilder.UseSqlServer(_connectionString);
    }
    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<OuterTable>().HasNoKey();
        modelBuilder.Entity<InnerTable>().HasNoKey();
    }
}

public class OuterTable
{
    public int? Outer1 { get; set; }
    public string? Outer2 { get; set; }
}

public class InnerTable
{
    public int? Inner1 { get; set; }
    public string? Inner2 { get; set; }
}

输出到SQL Server，即OuterTable、InnerTable。事实上，OuterTable 和 InnerTable 已经在 SQL Server 中使用空数据创建，并且它们没有主键。

无论如何，来源来自 Couchbase JSON 文档（使用 Kafka 接收消息），如下所示： enter image description here 所以我正在处理嵌套的 JSON 文档。其中一些具有内部结构。

不管怎样，别人告诉我，上面的代码背离了ORM的精神，因为应该避免在代码中执行原始的SQL命令。所以我遇到了以下情况。

using Confluent.Kafka;
using Microsoft.EntityFrameworkCore;
using System.Text.Json;
using System.Text.Json.Nodes;

string connectionString = "Server=localhost; Database=pubs; User ID=***; Password=***; TrustServerCertificate=True;";
string bootstrapServers = "localhost:9092";
string topicName = "cbsource";

var consumerConfig = new ConsumerConfig
{
    BootstrapServers = bootstrapServers,
    GroupId = "CB_SQL_consumer_ORM",
    AutoOffsetReset = AutoOffsetReset.Earliest
};

var cancellationTokenSource = new CancellationTokenSource();
Console.CancelKeyPress += (_, e) =>
{
    e.Cancel = true;
    cancellationTokenSource.Cancel();
};

var optionsBuilder = new DbContextOptionsBuilder<ApplicationDbContext>();
optionsBuilder.UseSqlServer(connectionString);

try
{
    using (var consumer = new ConsumerBuilder<Ignore, string>(consumerConfig).Build())
    {
        consumer.Subscribe(topicName);

        int i = 0;
        int j = 0;
        
        while (!cancellationTokenSource.Token.IsCancellationRequested)
        {
            try
            {
                var consumeResult = consumer.Consume(cancellationTokenSource.Token);

                if (consumeResult.Message.Value != null)
                {
                    Console.WriteLine($"Consumed message: {consumeResult.Message.Value}");

                    JsonObject? jsonObject = JsonSerializer.Deserialize<JsonObject>(consumeResult.Message.Value);

                    if (jsonObject != null)
                    {
                        int outerTableColumn1Value = int.TryParse(jsonObject["outer1"]?.ToString(), out int outer1Parsed) ? outer1Parsed : --i;
                        
                        string? outerTableColumn2Value = jsonObject["outer2"]?.ToString();

                        string? inner1Value = jsonObject["inner"]?["inner1"]?.ToString();
                        string? inner2Value = jsonObject["inner"]?["inner2"]?.ToString();

                        int innerTableColumn1Value = int.TryParse(inner1Value, out int inner1Parsed) ? inner1Parsed : --j;
        
                        string? innerTableColumn2Value = inner2Value;

                        using (var context = new ApplicationDbContext(optionsBuilder.Options))
                        {
                            using (var transaction = context.Database.BeginTransaction())
                            {
                                try
                                {
                                    var outerRow = await context.OuterTable
                                        .FirstOrDefaultAsync(o => o.Outer1 == outerTableColumn1Value);

                                    if (outerRow != null)
                                    {
                                        outerRow.Outer2 = outerTableColumn2Value;
                                        context.OuterTable.Update(outerRow);

                                        Console.WriteLine("Outer table row updated.");
                                    }
                                    else
                                    {
                                        var outerTable = new OuterTable
                                        {
                                            Outer1 = outerTableColumn1Value,
                                            Outer2 = outerTableColumn2Value
                                        };
                                        await context.OuterTable.AddAsync(outerTable);

                                        Console.WriteLine("Outer table row inserted.");
                                    }

                                    var innerRow = await context.InnerTable
                                        .FirstOrDefaultAsync(o => o.Inner1 == innerTableColumn1Value);

                                    if (innerRow != null)
                                    {
                                        innerRow.Inner2 = innerTableColumn2Value;
                                        context.InnerTable.Update(innerRow);

                                        Console.WriteLine("Inner table row updated.");
                                    }
                                    else
                                    {
                                        var innerTable = new InnerTable
                                        {
                                            Inner1 = innerTableColumn1Value,
                                            Inner2 = innerTableColumn2Value
                                        };
                                        await context.InnerTable.AddAsync(innerTable);

                                        Console.WriteLine("Inner table row inserted.");
                                    }

                                    await context.SaveChangesAsync();

                                    await transaction.CommitAsync();
                                }
                                catch (Exception ex)
                                {
                                    transaction.Rollback();

                                    Console.WriteLine($"Error: {ex.Message}. Transaction rolled back.");
                                }
                            }
                        }
                    }
                }
            }
            catch (ConsumeException e)
            {
                Console.WriteLine($"Error during consume: {e.Error.Reason}");
            }
        }
    }
}
catch (OperationCanceledException)
{
    Console.WriteLine("Consumer has been cancelled.");
}

public class ApplicationDbContext : DbContext
{
    public DbSet<OuterTable> OuterTable { get; set; }
    public DbSet<InnerTable> InnerTable { get; set; }

    public ApplicationDbContext(DbContextOptions<ApplicationDbContext> options) : base(options) { }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<OuterTable>().HasKey(o => o.Outer1);

        modelBuilder.Entity<InnerTable>().HasKey(i => i.Inner1);
    }
}

public class OuterTable
{
    public int? Outer1 { get; set; }
    public string? Outer2 { get; set; }
}

public class InnerTable
{
    public int? Inner1 { get; set; }
    public string? Inner2 { get; set; }
}

正如您在第二个代码中看到的那样，我输入了

modelBuilder.Entity<OuterTable>().HasKey(o => o.Outer1);

modelBuilder.Entity<InnerTable>().HasKey(i => i.Inner1);

但这实际上不是我打算这样做的，因为没有主键。但我需要使用这些 

Update
和 
AddAsync
以便我被迫拥有主键，如果没有，EF Core 将显示错误。因此，我被迫为这些 NULL 值输入一些值，我只是输入负整数。

我看到帖子建议使用复合键，但问题是，有些 JSON 文档根本没有外部/内部结构，但我仍然坚持将 NULL 值放入其中。所以合成键在我的情况下似乎不起作用。

这里我还附上了我的第一个代码生成的 SQL Server 中的表，以及我真正想要的。

enter image description here

enter image description here

c# sql-server entity-framework apache-kafka couchbase
1个回答
0
投票

在 EF Core 中，您无法创建没有任何主键的表。因为它用于对象的源。您不仅可以使用 Int32 值，还可以通过 GUID 和 String 链接它们。无论如何，您必须将键绑定到字典等值才能控制它

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