我正在编写一个无聊的应用程序来管理患者及其临床病史。我将SQLite与DbLinq库和DbMetal代码生成实用程序结合使用。这是从基础数据库中提取的通用代码中的两个类:

[Table(Name="main.Patients")]
public partial class Patient : System.ComponentModel.INotifyPropertyChanging, System.ComponentModel.INotifyPropertyChanged
{

    private static System.ComponentModel.PropertyChangingEventArgs emptyChangingEventArgs = new System.ComponentModel.PropertyChangingEventArgs("");

    private long _birthday;

    private string _firstName;

    private int _hasChildren;

    private System.Nullable<int> _id;

    private int _isMarried;

    private string _lastName;

    private string _profession;

    private EntitySet<ClinicCase> _clinicCases;

    private EntitySet<PatientAddress> _patientsAddresses;

    private EntitySet<PatientPhoneNumber> _patientsPhoneNumbers;

    #region Extensibility Method Declarations
    partial void OnCreated();

    partial void OnBirthdayChanged();

    partial void OnBirthdayChanging(long value);

    partial void OnFirstNameChanged();

    partial void OnFirstNameChanging(string value);

    partial void OnHasChildrenChanged();

    partial void OnHasChildrenChanging(int value);

    partial void OnIDChanged();

    partial void OnIDChanging(System.Nullable<int> value);

    partial void OnIsMarriedChanged();

    partial void OnIsMarriedChanging(int value);

    partial void OnLastNameChanged();

    partial void OnLastNameChanging(string value);

    partial void OnProfessionChanged();

    partial void OnProfessionChanging(string value);
    #endregion


    public Patient()
    {
        _clinicCases = new EntitySet<ClinicCase>(new Action<ClinicCase>(this.ClinicCases_Attach), new Action<ClinicCase>(this.ClinicCases_Detach));
        _patientsAddresses = new EntitySet<PatientAddress>(new Action<PatientAddress>(this.PatientsAddresses_Attach), new Action<PatientAddress>(this.PatientsAddresses_Detach));
        _patientsPhoneNumbers = new EntitySet<PatientPhoneNumber>(new Action<PatientPhoneNumber>(this.PatientsPhoneNumbers_Attach), new Action<PatientPhoneNumber>(this.PatientsPhoneNumbers_Detach));
        this.OnCreated();
    }

    [Column(Storage="_birthday", Name="Birthday", DbType="integer", AutoSync=AutoSync.Never, CanBeNull=false)]
    [DebuggerNonUserCode()]
    public long BirthdayBinaryDate
    {
        get
        {
            return this._birthday;
        }
        set
        {
            if ((_birthday != value))
            {
                this.OnBirthdayChanging(value);
                this.SendPropertyChanging();
                this._birthday = value;
                this.SendPropertyChanged("Birthday");
                this.OnBirthdayChanged();
            }
        }
    }

    [Column(Storage="_firstName", Name="FirstName", DbType="text", AutoSync=AutoSync.Never, CanBeNull=false)]
    [DebuggerNonUserCode()]
    public string FirstName
    {
        get
        {
            return this._firstName;
        }
        set
        {
            if (((_firstName == value)
                        == false))
            {
                this.OnFirstNameChanging(value);
                this.SendPropertyChanging();
                this._firstName = value;
                this.SendPropertyChanged("FirstName");
                this.OnFirstNameChanged();
            }
        }
    }

    [Column(Storage="_hasChildren", Name="HasChildren", DbType="integer", AutoSync=AutoSync.Never, CanBeNull=false)]
    [DebuggerNonUserCode()]
    public int HasChildren
    {
        get
        {
            return this._hasChildren;
        }
        set
        {
            if ((_hasChildren != value))
            {
                this.OnHasChildrenChanging(value);
                this.SendPropertyChanging();
                this._hasChildren = value;
                this.SendPropertyChanged("HasChildren");
                this.OnHasChildrenChanged();
            }
        }
    }

    [Column(Storage="_id", Name="ID", DbType="integer", IsPrimaryKey=true, IsDbGenerated=true, AutoSync=AutoSync.OnInsert)]
    [DebuggerNonUserCode()]
    public System.Nullable<int> ID
    {
        get
        {
            return this._id;
        }
        set
        {
            if ((_id != value))
            {
                this.OnIDChanging(value);
                this.SendPropertyChanging();
                this._id = value;
                this.SendPropertyChanged("ID");
                this.OnIDChanged();
            }
        }
    }

    [Column(Storage="_isMarried", Name="IsMarried", DbType="integer", AutoSync=AutoSync.Never, CanBeNull=false)]
    [DebuggerNonUserCode()]
    public int IsMarried
    {
        get
        {
            return this._isMarried;
        }
        set
        {
            if ((_isMarried != value))
            {
                this.OnIsMarriedChanging(value);
                this.SendPropertyChanging();
                this._isMarried = value;
                this.SendPropertyChanged("IsMarried");
                this.OnIsMarriedChanged();
            }
        }
    }

    [Column(Storage="_lastName", Name="LastName", DbType="text", AutoSync=AutoSync.Never, CanBeNull=false)]
    [DebuggerNonUserCode()]
    public string LastName
    {
        get
        {
            return this._lastName;
        }
        set
        {
            if (((_lastName == value)
                        == false))
            {
                this.OnLastNameChanging(value);
                this.SendPropertyChanging();
                this._lastName = value;
                this.SendPropertyChanged("LastName");
                this.OnLastNameChanged();
            }
        }
    }

    [Column(Storage="_profession", Name="Profession", DbType="text", AutoSync=AutoSync.Never)]
    [DebuggerNonUserCode()]
    public string Profession
    {
        get
        {
            return this._profession;
        }
        set
        {
            if (((_profession == value)
                        == false))
            {
                this.OnProfessionChanging(value);
                this.SendPropertyChanging();
                this._profession = value;
                this.SendPropertyChanged("Profession");
                this.OnProfessionChanged();
            }
        }
    }

    #region Children
    [Association(Storage="_clinicCases", OtherKey="PatientID", ThisKey="ID", Name="fk_ClinicCases_0")]
    [DebuggerNonUserCode()]
    public EntitySet<ClinicCase> ClinicCases
    {
        get
        {
            return this._clinicCases;
        }
        set
        {
            this._clinicCases = value;
        }
    }

    [Association(Storage="_patientsAddresses", OtherKey="PatientID", ThisKey="ID", Name="fk_PatientsAddresses_0")]
    [DebuggerNonUserCode()]
    public EntitySet<PatientAddress> Addresses
    {
        get
        {
            return this._patientsAddresses;
        }
        set
        {
            this._patientsAddresses = value;
        }
    }

    [Association(Storage="_patientsPhoneNumbers", OtherKey="PatientID", ThisKey="ID", Name="fk_PatientsPhoneNumbers_0")]
    [DebuggerNonUserCode()]
    public EntitySet<PatientPhoneNumber> PhoneNumbers
    {
        get
        {
            return this._patientsPhoneNumbers;
        }
        set
        {
            this._patientsPhoneNumbers = value;
        }
    }
    #endregion

    public event System.ComponentModel.PropertyChangingEventHandler PropertyChanging;

    public event System.ComponentModel.PropertyChangedEventHandler PropertyChanged;

    protected virtual void SendPropertyChanging()
    {
        System.ComponentModel.PropertyChangingEventHandler h = this.PropertyChanging;
        if ((h != null))
        {
            h(this, emptyChangingEventArgs);
        }
    }

    protected virtual void SendPropertyChanged(string propertyName)
    {
        System.ComponentModel.PropertyChangedEventHandler h = this.PropertyChanged;
        if ((h != null))
        {
            h(this, new System.ComponentModel.PropertyChangedEventArgs(propertyName));
        }
    }

    #region Attachment handlers
    private void ClinicCases_Attach(ClinicCase entity)
    {
        this.SendPropertyChanging();
        entity.Patient = this;
    }

    private void ClinicCases_Detach(ClinicCase entity)
    {
        this.SendPropertyChanging();
        entity.Patient = null;
    }

    private void PatientsAddresses_Attach(PatientAddress entity)
    {
        this.SendPropertyChanging();
        entity.Patient = this;
    }

    private void PatientsAddresses_Detach(PatientAddress entity)
    {
        this.SendPropertyChanging();
        entity.Patient = null;
    }

    private void PatientsPhoneNumbers_Attach(PatientPhoneNumber entity)
    {
        this.SendPropertyChanging();
        entity.Patient = this;
    }

    private void PatientsPhoneNumbers_Detach(PatientPhoneNumber entity)
    {
        this.SendPropertyChanging();
        entity.Patient = null;
    }
    #endregion
}

[Table(Name="main.PatientsAddresses")]
public partial class PatientAddress : System.ComponentModel.INotifyPropertyChanging, System.ComponentModel.INotifyPropertyChanged
{

    private static System.ComponentModel.PropertyChangingEventArgs emptyChangingEventArgs = new System.ComponentModel.PropertyChangingEventArgs("");

    private string _address;

    private string _domicileStatus;

    private System.Nullable<int> _patientID;

    private EntityRef<Patient> _patients = new EntityRef<Patient>();

    #region Extensibility Method Declarations
    partial void OnCreated();

    partial void OnAddressChanged();

    partial void OnAddressChanging(string value);

    partial void OnDomicileStatusChanged();

    partial void OnDomicileStatusChanging(string value);

    partial void OnPatientIDChanged();

    partial void OnPatientIDChanging(System.Nullable<int> value);
    #endregion


    public PatientAddress()
    {
        this.OnCreated();
    }

    [Column(Storage="_address", Name="Address", DbType="text", IsPrimaryKey=true, AutoSync=AutoSync.Never)]
    [DebuggerNonUserCode()]
    public string Address
    {
        get
        {
            return this._address;
        }
        set
        {
            if (((_address == value)
                        == false))
            {
                this.OnAddressChanging(value);
                this.SendPropertyChanging();
                this._address = value;
                this.SendPropertyChanged("Address");
                this.OnAddressChanged();
            }
        }
    }

    [Column(Storage="_domicileStatus", Name="DomicileStatus", DbType="text", AutoSync=AutoSync.Never)]
    [DebuggerNonUserCode()]
    public string DomicileStatus
    {
        get
        {
            return this._domicileStatus;
        }
        set
        {
            if (((_domicileStatus == value)
                        == false))
            {
                this.OnDomicileStatusChanging(value);
                this.SendPropertyChanging();
                this._domicileStatus = value;
                this.SendPropertyChanged("DomicileStatus");
                this.OnDomicileStatusChanged();
            }
        }
    }

    [Column(Storage="_patientID", Name="PatientID", DbType="integer", IsPrimaryKey=true, IsDbGenerated=true, AutoSync=AutoSync.Never)]
    [DebuggerNonUserCode()]
    public System.Nullable<int> PatientID
    {
        get
        {
            return this._patientID;
        }
        set
        {
            if ((_patientID != value))
            {
                if (_patients.HasLoadedOrAssignedValue)
                {
                    throw new System.Data.Linq.ForeignKeyReferenceAlreadyHasValueException();
                }
                this.OnPatientIDChanging(value);
                this.SendPropertyChanging();
                this._patientID = value;
                this.SendPropertyChanged("PatientID");
                this.OnPatientIDChanged();
            }
        }
    }

    #region Parents
    [Association(Storage="_patients", OtherKey="ID", ThisKey="PatientID", Name="fk_PatientsAddresses_0", IsForeignKey=true)]
    [DebuggerNonUserCode()]
    public Patient Patient
    {
        get
        {
            return this._patients.Entity;
        }
        set
        {
            if (((this._patients.Entity == value)
                        == false))
            {
                if ((this._patients.Entity != null))
                {
                    Patient previousPatients = this._patients.Entity;
                    this._patients.Entity = null;
                    previousPatients.Addresses.Remove(this);
                }
                this._patients.Entity = value;
                if ((value != null))
                {
                    value.Addresses.Add(this);
                    _patientID = value.ID;
                }
                else
                {
                    _patientID = null;
                }
            }
        }
    }
    #endregion

    public event System.ComponentModel.PropertyChangingEventHandler PropertyChanging;

    public event System.ComponentModel.PropertyChangedEventHandler PropertyChanged;

    protected virtual void SendPropertyChanging()
    {
        System.ComponentModel.PropertyChangingEventHandler h = this.PropertyChanging;
        if ((h != null))
        {
            h(this, emptyChangingEventArgs);
        }
    }

    protected virtual void SendPropertyChanged(string propertyName)
    {
        System.ComponentModel.PropertyChangedEventHandler h = this.PropertyChanged;
        if ((h != null))
        {
            h(this, new System.ComponentModel.PropertyChangedEventArgs(propertyName));
        }
    }
}


我使用以下代码为患者添加地址:

PatientAddress address = new PatientAddress();
address.Address = txtAddress.Text;
address.DomicileStatus = cmbDomicileStatus.Text;
currentPatient.Addresses.Add(address);

Database.Source.PatientsAddresses.InsertOnSubmit(address);
Database.Source.SubmitChanges();


Database.Source是在生成的代码中扩展DataContext的类的实例。在SubmitChanges上,我收到以下异常:

“在Nullable(Int32)和Int32之间没有定义相等的运算符。”

该消息不是逐词报告的,但是含义是相同的。堆栈跟踪指向DbLinq代码,更确切地说,指向源文件DbLinq.Data.Linq.DataContext.cs的第709行。您可以在以下位置找到源文件:http://dblinq.codeplex.com/SourceControl/changeset/view/16800#314775(在SetEntityRefQueries(对象实体)方法的主体下)。
我看到将外键值与表达式树中的常量进行比较时出现了问题,但是我无法获得有关此信息的其他信息。您能帮我找到问题吗?

N.B .:字段地址。PatientID(外键)实际上是在调用SubmitChanges之前设置为正确的值。

最佳答案

正如我在上面的注释中提到的(在此重复我的操作,以便可以链接图像),您的主键不应为空。尽管我不使用DbLinq,但是您的映射中应该有一个可以更改以设置它的属性,因此我不能直接给您截图。相反,它在LINQ-2-SQL DBML设计器(左)和Entity Framework EDMX设计器(右)中。





我不确定您的删除问题-好像它应该对我有用。您可以编辑问题以包含整个删除代码段吗?作为初步猜测,您要么创建一个新对象(而不是加载一个对象),然后尝试删除它,要么删除关联而不删除对象。

通常,我永远不会从数据库中删除它,因为我会标记为非活动。这样“取消删除”要容易得多。

10-07 12:25