在MySQL Linq查询EF6中使用多个Include（）方法时出现FormatException

Question

I'm trying to execute a LINQ query and using Include() multiple times to pull related information.

It works fine if I do the following query:

var usersQuizzes = this.Context.EntitySet<Quiz>()
                    .Include(x => x.Questions)
                    .Include(x => x.QuizVersion)
                    .Include(x => x.QuizPasswords)
                    .Include(x => x.QuizVersion.Questions)
                    .Take(20)
                    .ToList();

But I get an error if I have it like this:

var usersQuizzes = this.Context.EntitySet<Quiz>()
                    .Include(x => x.Questions)
                    .Include(x => x.QuizVersion)
                    .Include(x => x.QuizPasswords)
                    .Include(x => x.QuizVersion.Questions)
                    .Include(x => x.QuizVersions) // Added this
                    .Take(20)
                    .ToList();

or this:

var usersQuizzes = this.Context.EntitySet<Quiz>()
                    .Include(x => x.Questions)
                    .Include(x => x.QuizVersion)
                    .Include(x => x.QuizPasswords)
                    .Include(x => x.QuizVersion.Questions)
                    .Include(x => x.ResultDescriptions) // Added this instead
                    .Take(20)
                    .ToList();

or this:

 var usersQuizzes = this.Context.EntitySet<Quiz>()
                        .Include(x => x.QuizVersions)
                        .Include(x => x.ResultDescriptions)
                        .Include(x => x.QuizPasswords)
                        .Take(20)
                        .ToList();

But it works if I strip out QuizPasswords:

 var usersQuizzes = this.Context.EntitySet<Quiz>()
                        .Include(x => x.QuizVersions)
                        .Include(x => x.ResultDescriptions)
                        .Take(20)
                        .ToList();

Error Message

An exception of type 'System.FormatException' occurred in mscorlib.dll but was not handled in user code

Additional information: String was not recognized as a valid Boolean.

Quiz.cs

public partial class Quiz
    {
        public Quiz()
        {
            this.TakerAnswers = new List<TakerAnswer>();
            this.FeaturedQuizzes = new List<FeaturedQuiz>();
            this.PersonalityOutcomes = new List<PersonalityOutcome>();
            this.PossibleAnswers = new List<PossibleAnswer>();
            this.Questions = new List<Question>();
            this.QuizLinks = new List<QuizLink>();
            this.QuizPasswords = new List<QuizPassword>();
            this.QuizSubmissions = new List<QuizSubmission>();
            this.QuizVersions = new List<QuizVersion>();
            this.ResultDescriptions = new List<ResultDescription>();
            this.Takers = new List<Taker>();
            this.PersonalityResultImages = new List<PersonalityResultImage>();
            this.PersonalityShareImages = new List<PersonalityShareImage>();
        }

        public int Id { get; set; }
        public int UserId { get; set; }
        public Nullable<int> QuizVersionId { get; set; }
        public string IpAddress { get; set; }

        [DefaultValue(false)]
        public bool IsPublic { get; set; }

        [DefaultValue(QuizType.Scored)]
        public QuizType QuizType { get; set; }

        public int CreatedTime { get; set; }
        public Nullable<int> BackgroundId { get; set; }

        [Index(IsUnique = true)]
        public string UrlId { get; set; }

        [DefaultValue(false)]
        public bool PasswordsDisabled { get; set; }

        [DefaultValue(false)]
        public bool SharedFacebook { get; set; }

        [DefaultValue(false)]
        public bool SharedTwitter { get; set; }

        [DefaultValue(false)]
        public bool Deleted { get; set; }

        [DefaultValue(false)]
        public bool ShowCorrections { get; set; }

        [DefaultValue(true)]
        public bool ShowBreakdown { get; set; }
        public string Thumbnail { get; set; }
        public string ShareImage { get; set; }
        public Nullable<int> QuizLinkId { get; set; }

        [DefaultValue(false)]
        public bool ForceShareImage { get; set; }

        [DefaultValue(0)]
        public int ShareCount { get; set; }

        [DefaultValue(BackgroundAlign.Top)]
        public BackgroundAlign BackgroundAlign { get; set; }

        public string BackgroundColour { get; set; }
        public string TextColour { get; set; }
        public virtual ICollection<TakerAnswer> TakerAnswers { get; set; }
        public virtual ICollection<FeaturedQuiz> FeaturedQuizzes { get; set; }
        public virtual ICollection<PersonalityOutcome> PersonalityOutcomes { get; set; }
        public virtual ICollection<PossibleAnswer> PossibleAnswers { get; set; }
        public virtual ICollection<Question> Questions { get; set; }
        public virtual ICollection<QuizLink> QuizLinks { get; set; }
        public virtual ICollection<QuizPassword> QuizPasswords { get; set; }
        public virtual ICollection<QuizSubmission> QuizSubmissions { get; set; }
        public virtual ICollection<QuizVersion> QuizVersions { get; set; }
        public virtual QuizBackground QuizBackground { get; set; }
        public virtual QuizLink QuizLink { get; set; }
        public virtual QuizVersion QuizVersion { get; set; }
        public virtual User User { get; set; }
        public virtual ICollection<ResultDescription> ResultDescriptions { get; set; }
        public virtual ICollection<Taker> Takers { get; set; }
        public virtual ICollection<PersonalityResultImage> PersonalityResultImages { get; set; }
        public virtual ICollection<PersonalityShareImage> PersonalityShareImages { get; set; }
    }

QuizVersion.cs

public partial class QuizVersion
    {
        public QuizVersion()
        {
            this.TakerAnswers = new List<TakerAnswer>();
            this.FeaturedQuizzes = new List<FeaturedQuiz>();
            this.PersonalityOutcomes = new List<PersonalityOutcome>();
            this.PossibleAnswers = new List<PossibleAnswer>();
            this.Questions = new List<Question>();
            this.QuizSubmissions = new List<QuizSubmission>();
            this.Takers = new List<Taker>();
        }

        public int Id { get; set; }
        public int QuizId { get; set; }
        public string QuizName { get; set; }
        public string QuizIntro { get; set; }
        public string IpAddress { get; set; }
        public bool Public { get; set; }
        public int CreatedTime { get; set; }
        public virtual ICollection<TakerAnswer> TakerAnswers { get; set; }
        public virtual ICollection<FeaturedQuiz> FeaturedQuizzes { get; set; }
        public virtual ICollection<PersonalityOutcome> PersonalityOutcomes { get; set; }
        public virtual ICollection<PossibleAnswer> PossibleAnswers { get; set; }
        public virtual ICollection<Question> Questions { get; set; }
        public virtual Quiz Quiz { get; set; }
        public virtual ICollection<QuizSubmission> QuizSubmissions { get; set; }
        public virtual ICollection<Taker> Takers { get; set; }
    }

ResultDescription.cs

public partial class ResultDescription
{
    public int Id { get; set; }
    public int QuizId { get; set; }
    public Nullable<int> Percentage { get; set; }
    public string Description { get; set; }

    [DefaultValue(false)]
    public bool Deleted { get; set; }

    public virtual Quiz Quiz { get; set; }
}

I thought it might be some dodgy values within my database, but I've checked all of the bool type values within my POCO classes and they all seem to be type tinyint(1) and set to either 1 or 0 and no nulls.

What could be causing this error?

Answer 1

I had the same problem and used this workaround, in your first error example:

var usersQuizzes = this.Context.EntitySet<Quiz>()
                .Include(x => x.Questions)
                .Include(x => x.QuizVersion)
                .Include(x => x.QuizPasswords)
                .Include(x => x.QuizVersion.Questions);

this.Context.Entry(userQuizes).Collection("QuizVersions").Load();

userQuizes.Take(20).ToList();

Answer 2

我设法通过切换包含顺序并将错误的包含放在首位来使我的代码正常工作（在您的情况下为x.QuizPasswords）

Answer 3

I found a solution forcing the property to 'bit' default 'false'. I changed the data type in Mysql. Tinyint -> Bit.

[Column("Active", TypeName = "bit")]
[DefaultValue(false)]
public bool Active { get; set; 

The link reference:

Entity Framework MySQL tinyint(1) System.Boolean.Parse FormatException