EF6 with MySQL. The given key was not present in t

2020-04-18 05:51发布

问题:

I have Asp.Net MVC 5 application using Code First Entity Framework 6 linked to MySQL database.

When I created the database first time, it works fine. But when I make a change to the model then add migration. An error shows after (Update-Database).

This is the error:

        PM> Update-Database 
        System.Collections.Generic.KeyNotFoundException: The given key was not present in the dictionary.
           at System.Collections.Generic.Dictionary`2.get_Item(TKey key)
           at MySql.Data.MySqlClient.MySqlConnectionStringBuilder.<>c.<.cctor>b__2_7(MySqlConnectionStringBuilder msb, MySqlConnectionStringOption sender)
           at MySql.Data.MySqlClient.MySqlConnectionStringBuilder.get_Item(String keyword)
           at MySql.Data.MySqlClient.MySqlConnectionStringBuilder.GetConnectionString(Boolean includePass)
           at MySql.Data.MySqlClient.MySqlConnection.get_ConnectionString()
           at System.Data.Entity.Infrastructure.Interception.DbConnectionDispatcher.<GetConnectionString>b__12(DbConnection t, DbConnectionInterceptionContext`1 c)
           at System.Data.Entity.Infrastructure.Interception.InternalDispatcher`1.Dispatch[TTarget, TInterceptionContext, TResult](TTarget target, Func`3 operation, TInterceptionContext interceptionContext, Action`3 executing, Action`3 executed)
           at System.Data.Entity.Infrastructure.Interception.DbConnectionDispatcher.GetConnectionString(DbConnection connection, DbInterceptionContext interceptionContext)
           at System.Data.Entity.Internal.InternalConnection.GetStoreConnectionString(DbConnection connection)
           at System.Data.Entity.Internal.InternalConnection.OnConnectionInitialized()
           at System.Data.Entity.Internal.EagerInternalConnection..ctor(DbContext context, DbConnection existingConnection, Boolean connectionOwned)
           at System.Data.Entity.DbContext..ctor(DbConnection existingConnection, Boolean contextOwnsConnection)
           at System.Data.Entity.Migrations.History.HistoryContext..ctor(DbConnection existingConnection, String defaultSchema)
           at MySql.Data.Entity.MySqlHistoryContext..ctor(DbConnection existingConnection, String defaultSchema)
           at code_first_mysql.Migrations.Configuration.<>c.<.ctor>b__0_0(DbConnection conn, String schema) in C:\Users\User\Documents\Tree\New Backend\code first mysql\Migrations\Configuration.cs:line 16
           at System.Data.Entity.Migrations.History.HistoryRepository.CreateContext(DbConnection connection, String schema)
           at System.Data.Entity.Migrations.History.HistoryRepository.<GetUpgradeOperations>d__16.MoveNext()
           at System.Linq.Enumerable.Any[TSource](IEnumerable`1 source)
           at System.Data.Entity.Migrations.DbMigrator.UpdateInternal(String targetMigration)
           at System.Data.Entity.Migrations.DbMigrator.<>c__DisplayClassc.<Update>b__b()
           at System.Data.Entity.Migrations.Infrastructure.MigratorScriptingDecorator.EnsureDatabaseExists(Action mustSucceedToKeepDatabase)
           at System.Data.Entity.Migrations.DbMigrator.Update(String targetMigration)
           at System.Data.Entity.Migrations.Infrastructure.MigratorBase.Update(String targetMigration)
           at System.Data.Entity.Migrations.Infrastructure.MigratorBase.Update(String targetMigration)
           at System.Data.Entity.Migrations.Infrastructure.MigratorScriptingDecorator.ScriptUpdate(String sourceMigration, String targetMigration)
           at System.Data.Entity.Migrations.Design.ToolingFacade.ScriptUpdateRunner.Run()
           at System.AppDomain.DoCallBack(CrossAppDomainDelegate callBackDelegate)
           at System.AppDomain.DoCallBack(CrossAppDomainDelegate callBackDelegate)
           at System.Data.Entity.Migrations.Design.ToolingFacade.Run(BaseRunner runner)
           at System.Data.Entity.Migrations.Design.ToolingFacade.ScriptUpdate(String sourceMigration, String targetMigration, Boolean force)
           at System.Data.Entity.Migrations.UpdateDatabaseCommand.<>c__DisplayClass2.<.ctor>b__0()
           at System.Data.Entity.Migrations.MigrationsDomainCommand.Execute(Action command)
        The given key was not present in the dictionary.

These are my MySQL Configuration Classes:

internal sealed class Configuration : DbMigrationsConfiguration<ApplicationDbContext>
{
    public Configuration()
    {
        AutomaticMigrationsEnabled = false;
        SetSqlGenerator("MySql.Data.MySqlClient", new MySqlMigrationSqlGenerator());
        SetHistoryContextFactory("MySql.Data.MySqlClient", (conn, schema) => new MySqlHistoryContext(conn, schema));
        CodeGenerator = new MySqlMigrationCodeGenerator();
    }

    protected override void Seed(ApplicationDbContext context)
    {}
}


public class MySqlConfiguration: DbConfiguration
{

    public MySqlConfiguration()
    {
        SetHistoryContext("MySql.Data.MySqlClient", (conn, schema) => new MySqlHistoryContext(conn, schema));
    }

}



public class MySqlHistoryContext : HistoryContext 
{
    public MySqlHistoryContext(DbConnection existingConnection, string defaultSchema) : base(existingConnection, defaultSchema)
    {
    }

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        base.OnModelCreating(modelBuilder);
        modelBuilder.Entity<HistoryRow>().Property(h => h.MigrationId).HasMaxLength(100).IsRequired();
        modelBuilder.Entity<HistoryRow>().Property(h => h.ContextKey).HasMaxLength(200).IsRequired();
    }
}

 public class MySqlInitializer : IDatabaseInitializer<ApplicationDbContext>
{

    public void InitializeDatabase(ApplicationDbContext context)
    {
        if (!context.Database.Exists())
        {
            // if database did not exist before - create it
            context.Database.Create();
        }
        else
        {
            // query to check if MigrationHistory table is present in the database 
            var migrationHistoryTableExists = ((IObjectContextAdapter)context).ObjectContext.ExecuteStoreQuery<int>(
            string.Format(
              "SELECT COUNT(*) FROM information_schema.tables WHERE table_schema = '{0}' AND table_name = '__MigrationHistory'", "mydb"));

            // if MigrationHistory table is not there (which is the case first time we run) - create it
            if (migrationHistoryTableExists.FirstOrDefault() == 0)
            {
                context.Database.Delete();
                context.Database.Create();
            }
        }
    }
}

回答1:

As you see from the first lines of the error,

MySql.Data.MySqlClient.MySqlConnectionStringBuilder.<>c.<.cctor>b__2_7(MySqlConnectionStringBuilder msb, MySqlConnectionStringOption sender) at MySql.Data.MySqlClient.MySqlConnectionStringBuilder.get_Item(String keyword)

the error has to do with the ConnectionString. The problem is the ConnectionString contains keys that can't be read.

Try to clean up the ConnectionString so that it has only

  1. server
  2. user id
  3. password
  4. database

In my case, the ConnectionString had an extra key integrated security. When this was removed Update-Database started working fine. Depending on your case however, this might and might not be the key that caused the error.

So again my proposed and guaranteed solution, go through ConnectionString and simplify it so that it contains only the 4 keys mentioned above.



回答2:

Bug 75172 It is a bug reported in version 6.9.4,but I review it in 6.9.11.



回答3:

Don't apply the newest mysql tools

  1. Close Visual studio 2017

  2. Uninstall mysql-for-visualstudio 2.0.5 Then, install mysql-for-visualstudio 1.2.8

  3. Uninstall mysql-connector-net-8.0.17 Then, install mysql-connector-net-6.9.10. Find the mysql.data.dll, MySql.Data.Entity.EF6.dll in %Program Files (x86)%\MySQL\MySQL Connector Net 6.9.10\Assemblies\v4.5 Add to reference

  4. Open nuget in references, downgrade EntityFramework 6 to EntityFramework 5