使用Pomelo EntityFrameworkCore MySql的EF Core 6无法创建数据库

Question

我是使用EF核心6与Pomelo.EntityFrameworkCore.MySql和代码优先。连接字符串中有以下代码。

public sealed partial class MyDbContext : DbContext
{
    public MyDbContext(DbContextOptions<MyDbContext> options)
        : base(options)
    {
        Database.Migrate();

        ChangeTracker.LazyLoadingEnabled = false;
    }

当我运行我的应用程序并且MyDbContext被初始化时，我第一次得到Unknown database 'mydatabase'数据库不存在，但是现在用来创建它的迁移

用户可以对mysql进行管理访问，因此这不是用户权限问题。

这是堆栈跟踪

   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd(Task task)
   at System.Threading.Tasks.ValueTask`1.get_Result()
   at System.Runtime.CompilerServices.ConfiguredValueTaskAwaitable`1.ConfiguredValueTaskAwaiter.GetResult()
   at MySqlConnector.Core.ResultSet.<ReadResultSetHeaderAsync>d__2.MoveNext() in /_/src/MySqlConnector/Core/ResultSet.cs:line 44
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at MySqlConnector.MySqlDataReader.ActivateResultSet(CancellationToken cancellationToken) in /_/src/MySqlConnector/MySqlDataReader.cs:line 130
   at MySqlConnector.MySqlDataReader.<CreateAsync>d__106.MoveNext() in /_/src/MySqlConnector/MySqlDataReader.cs:line 457
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1.ConfiguredTaskAwaiter.GetResult()
   at MySqlConnector.Core.CommandExecutor.<ExecuteReaderAsync>d__0.MoveNext() in /_/src/MySqlConnector/Core/CommandExecutor.cs:line 56
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1.ConfiguredTaskAwaiter.GetResult()
   at MySqlConnector.MySqlCommand.<ExecuteNonQueryAsync>d__78.MoveNext() in /_/src/MySqlConnector/MySqlCommand.cs:line 282
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
   at MySqlConnector.MySqlCommand.ExecuteNonQuery() in /_/src/MySqlConnector/MySqlCommand.cs:line 101
   at Pomelo.EntityFrameworkCore.MySql.Storage.Internal.MySqlDatabaseCreator.<>c__DisplayClass18_0.<Exists>b__0(DateTime giveUp)

我的连接字符串是"DbConnection": "server=127.0.0.1;port=3306;database=mydatabase;uid=muusername;pwd=mypassword;"

这里有什么问题？

Answer 1

这不是抛出到代码中的异常，而是被Pomelo捕获的内部异常。

柚子正在尝试打开数据库，测试数据库是否存在。如果该异常不存在，则该异常将由MySQL抛出，并在Pomelo创建数据库之前被Pomelo捕获。

因此，很有可能，您的IDE设置可以中断所有(包括内部)异常。只要继续运行这个应用程序，它就可以正常工作并创建数据库。