EF 4.4 Preventing AutoGen Navigation Properties and/or Relationships - entity-framework

Question

I started a db schema using EF and ran into multiple issues when tring to mannually modify the CLR's and/or db tables. First was a "Employee_ID" column that EF placed in a table. I deleted it, the dbo.EdmMetaData and the dbo.__MigrationHistory tables and fumbled through the run-time errors that insued. Now, I'm grapling with the following error:
A dependent property in a ReferentialConstraint is mapped to a store-generated column. Column: 'EmployeeID'.
My implementation uses a TimeCardEntity CLR that has 3 computed columns. These columns just so happens to map to another table's Primary Key. This other table is EmployeeRecord.
GOAL) I don't WANT EF to auto map thse 3 columns. I intend to fill them myself due to the complications EF offers, but I can't tell EF to stop creating navigation relationships and/or referential constraints.
Point #1) I have a EmployeeRecord table that has a Guid ID primary key, it maps to CLR class EmployeeRecord
Point #2) I have a TimeCardEntity table that has has 3 computed columns called EmployeeID, ManagerID, DivisionManagerID that relate back to EmployeeRecord. All are NULL declared but EmployeeID is required, obviously, because you can't have a time card without declaring the employee. The ManagerID and DivisionManagerID get filled later.
Point #3) Please don't ask me "Why are these computed?", because there is a reason. I alos feel it is illrelevant to the issue. In short, computed EmployeeID's (whether employee, manager or division mananger), are stored in an xml property with the data of approval and signature of employee - which provides non reputiation.
Point #4) I have 3 stored functions called fxGetEmployeeID(xml), fxGetManagerID(xml), and getDivisonManagerID(xml). Each of these are used in the computed columns EmployeeID, ManagerID and DivisionManagerID respectively.
Here is the class declarations simplified for brevity:
public enum TimeCardEmployeeTypeEnum {
Employee,
Manager,
DivisionManager
}
[DataContract]
[Serializable]
[Table("EmployeeRecord", Schema = "TimeCard")]
public class EmployeeRecord {
#region Exposed Propert(y|ies)
[DataMember]
public Guid ID { get; set; }
/// <summary>
/// Customers internal company employee ID. Can be null, SSN, last 4, or what ever...
/// I included it just in case it was part of my pains...
/// </summary>
[CustomValidation(typeof(ModelValidator), "EmployeeRecord_EmployeeID", ErrorMessage = "Employee ID is not valid.")]
public string EmployeeID { get; set; }
#endregion
}
[DataContract]
[Serializable]
[Table("TimeCardEntry", Schema = "TimeCard")]
public class TimeCardEntry {
#region Member Field(s)
[NonSerialized]
XDocument m_TimeEntries;
#endregion
#region Con/Destructor(s)
public TimeCardEntry() {
this.m_TimeEntries = "<root />".ToXDocument();
}
public TimeCardEntry(Guid employeeID) {
if (employeeID == Guid.Empty)
throw new ArgumentNullException("employeeID");
this.m_TimeEntries = "<root />".ToXDocument();
this.EmployeeID = employeeID;
}
#endregion
#region Exposed Propert(y|ies)
[NotMapped]
[IgnoreDataMember]
public XDocument TimeEntries {
get {
if (this.m_TimeEntries == null) {
if (!string.IsNullOrEmpty(this.TimeEntriesXml))
this.m_TimeEntries = this.TimeEntriesXml.ToXDocument();
}
return this.m_TimeEntries;
}
set {
this.m_TimeEntries = value;
if (this.m_TimeEntries != null)
this.TimeEntriesXml = this.m_TimeEntries.ToString();
else
this.TimeEntriesXml = null;
this.OnPropertyChanged("TimeEntriesXml");
this.OnPropertyChanged("TimeEntries");
}
}
[DataMember]
[EditorBrowsable(EditorBrowsableState.Never)]
[Required]
public string TimeEntriesXml {
get {
if (this.m_TimeEntries == null)
return null;
return this.m_TimeEntries.ToString();
}
set {
this.m_TimeEntries = value.ToXDocument();
this.OnPropertyChanged("TimeEntriesXml");
this.OnPropertyChanged("TimeEntries");
}
}
[IgnoreDataMember]
[DatabaseGenerated(System.ComponentModel.DataAnnotations.Schema.DatabaseGeneratedOption.Computed)]
public Guid? EmployeeID {
get {
var attribute = this.m_TimeEntries.Root.Attribute("EmployeeID");
if (attribute != null)
return (Guid)attribute;
return null;
}
set {
if (this.ValidateSignature(TimeCardEmployeeTypeEnum.Manager))
throw new ArgumentException("Property cannot be changed once the manager signature has been set.", "EmployeeID");
if (value != null && value.Value != Guid.Empty)
this.m_TimeEntries.Root.SetAttributeValue("EmployeeID", value);
else {
var attribute = this.m_TimeEntries.Root.Attribute("EmployeeID");
if (attribute != null)
attribute.Remove();
}
this.OnPropertyChanged("EmployeeID");
}
}
public virtual EmployeeRecord Employee { get; set; }
[NotMapped]
[IgnoreDataMember]
public DateTime? EmployeeApprovalDate {
get {
var attribute = this.m_TimeEntries.Root.Attribute("EmployeeApprovalDate");
if (attribute != null)
return (DateTime)attribute;
return null;
}
set {
if (this.ValidateSignature(TimeCardEmployeeTypeEnum.Manager))
throw new ArgumentException("Property cannot be changed once the manager signature has been set.", "EmployeeApprovalDate");
if (value.HasValue)
this.m_TimeEntries.Root.SetAttributeValue("EmployeeApprovalDate", value);
else {
var attribute = this.m_TimeEntries.Root.Attribute("EmployeeApprovalDate");
if (attribute != null)
attribute.Remove();
}
this.OnPropertyChanged("EmployeeApprovalDate");
}
}
[NotMapped]
[IgnoreDataMember]
public byte[] EmployeeSignature {
get {
var attribute = this.m_TimeEntries.Root.Attribute("EmployeeSignature");
if (attribute != null)
return Convert.FromBase64String((string)attribute);
return null;
}
set {
if (this.ValidateSignature(TimeCardEmployeeTypeEnum.Manager))
throw new ArgumentException("Property cannot be changed once the manager signature has been set.", "EmployeeSignature");
if (value != null) {
if (value.Length > 1024)
throw new ArgumentException("Signature cannot be larger than 1KB.", "EmployeeSignature");
this.m_TimeEntries.Root.SetAttributeValue("EmployeeSignature", Convert.ToBase64String(value));
} else {
var attribute = this.m_TimeEntries.Root.Attribute("EmployeeApprovalDate");
if (attribute != null)
attribute.Remove();
}
this.OnPropertyChanged("EmployeeSignature");
}
}
[IgnoreDataMember]
[DatabaseGenerated(System.ComponentModel.DataAnnotations.Schema.DatabaseGeneratedOption.Computed)]
public Guid? ManagerID {
get {
var attribute = this.m_TimeEntries.Root.Attribute("ManagerID");
if (attribute != null)
return (Guid)attribute;
return null;
}
set {
if (this.ValidateSignature(TimeCardEmployeeTypeEnum.DivisionManager))
throw new ArgumentException("Property cannot be changed once the division manager signature has been set.", "ManagerID");
if (value.HasValue) {
if (value.Value == Guid.Empty)
throw new ArgumentNullException("ManagerID");
this.m_TimeEntries.Root.SetAttributeValue("ManagerID", value);
} else {
var attribute = this.m_TimeEntries.Root.Attribute("ManagerID");
if (attribute != null)
attribute.Remove();
}
this.OnPropertyChanged("ManagerID");
}
}
public virtual EmployeeRecord Manager { get; set; }
[NotMapped]
[IgnoreDataMember]
public DateTime? ManagerApprovalDate {
get {
var attribute = this.m_TimeEntries.Root.Attribute("ManagerApprovalDate");
if (attribute != null)
return (DateTime)attribute;
return null;
}
set {
if (this.ValidateSignature(TimeCardEmployeeTypeEnum.DivisionManager))
throw new ArgumentException("Property cannot be changed once the division manager signature has been set.", "ManagerApprovalDate");
if (value.HasValue)
this.m_TimeEntries.Root.SetAttributeValue("ManagerApprovalDate", value);
else {
var attribute = this.m_TimeEntries.Root.Attribute("ManagerApprovalDate");
if (attribute != null)
attribute.Remove();
}
this.OnPropertyChanged("ManagerApprovalDate");
}
}
[NotMapped]
[IgnoreDataMember]
public byte[] ManagerSignature {
get {
var attribute = this.m_TimeEntries.Root.Attribute("ManagerSignature");
if (attribute != null)
return Convert.FromBase64String((string)attribute);
return null;
}
set {
if (this.ValidateSignature(TimeCardEmployeeTypeEnum.DivisionManager))
throw new ArgumentException("Property cannot be changed once the division manager signature has been set.", "ManagerSignature");
if (value != null) {
if (value.Length > 1024)
throw new ArgumentException("Signature cannot be larger than 1KB.", "ManagerSignature");
this.m_TimeEntries.Root.SetAttributeValue("ManagerSignature", Convert.ToBase64String(value));
} else {
var attribute = this.m_TimeEntries.Root.Attribute("ManagerSignature");
if (attribute != null)
attribute.Remove();
}
this.OnPropertyChanged("ManagerSignature");
}
}
[IgnoreDataMember]
[DatabaseGenerated(System.ComponentModel.DataAnnotations.Schema.DatabaseGeneratedOption.Computed)]
public Guid? DivisionManagerID {
get {
var attribute = this.m_TimeEntries.Root.Attribute("DivisionManagerID");
if (attribute != null)
return (Guid)attribute;
return null;
}
set {
if (value.HasValue) {
if (value.Value == Guid.Empty)
throw new ArgumentNullException("DivisionManagerID");
this.m_TimeEntries.Root.SetAttributeValue("DivisionManagerID", value);
} else {
var attribute = this.m_TimeEntries.Root.Attribute("DivisionManagerID");
if (attribute != null)
attribute.Remove();
}
this.OnPropertyChanged("DivisionManagerID");
}
}
public virtual EmployeeRecord DivisionManager { get; set; }
[NotMapped]
[IgnoreDataMember]
public DateTime? DivisionManagerApprovalDate {
get {
var attribute = this.m_TimeEntries.Root.Attribute("DivisionManagerApprovalDate");
if (attribute != null)
return (DateTime)attribute;
return null;
}
set {
if (value.HasValue)
this.m_TimeEntries.Root.SetAttributeValue("DivisionManagerApprovalDate", value);
else {
var attribute = this.m_TimeEntries.Root.Attribute("DivisionManagerApprovalDate");
if (attribute != null)
attribute.Remove();
}
this.OnPropertyChanged("DivisionManagerApprovalDate");
}
}
[NotMapped]
[IgnoreDataMember]
public byte[] DivisionManagerSignature {
get {
var attribute = this.m_TimeEntries.Root.Attribute("DivisionManagerSignature");
if (attribute != null)
return Convert.FromBase64String((string)attribute);
return null;
}
set {
if (value != null) {
if (value.Length > 1024)
throw new ArgumentException("Signature cannot be larger than 1KB.", "DivisionManagerSignature");
this.m_TimeEntries.Root.SetAttributeValue("DivisionManagerSignature", Convert.ToBase64String(value));
} else {
var attribute = this.m_TimeEntries.Root.Attribute("DivisionManagerSignature");
if (attribute != null)
attribute.Remove();
}
this.OnPropertyChanged("DivisionManagerSignature");
}
}
#endregion
}
This is the db context declaration
public sealed class DatabaseContext : DbContext {
public DatabaseContext(bool autoDetectChangesEnabled = false, bool lazyLoadingEnabled = false, bool proxyCreationEnabled = false, bool validateOnSaveEnabled = false) {
this.Configuration.AutoDetectChangesEnabled = autoDetectChangesEnabled;
this.Configuration.LazyLoadingEnabled = lazyLoadingEnabled;
this.Configuration.ProxyCreationEnabled = proxyCreationEnabled;
this.Configuration.ValidateOnSaveEnabled = validateOnSaveEnabled;
}
public DbSet<EmployeeRecord> EmployeeRecords { get; set; }
public DbSet<TimeCardEntry> TimeCards { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder) {
modelBuilder.Conventions.Remove<System.Data.Entity.Infrastructure.IncludeMetadataConvention>();
}
}
UPDATE
I have to add another observed behavior of EF. When I add the "NotMappedAttribute" to the EmployeeID column of TimeCardEntry, I get another issue. The EF addes a "Employee_ID" column back to the auto-gen schema. See the TSQL Profile Trace below:
exec sp_executesql N'SELECT
[Limit1].[C1] AS [C1],
[Limit1].[ID] AS [ID],
[Limit1].[TimeEntriesXml] AS [TimeEntriesXml],
[Limit1].[ManagerID] AS [ManagerID],
[Limit1].[DivisionManagerID] AS [DivisionManagerID],
[Limit1].[CreatedBy] AS [CreatedBy],
[Limit1].[Created] AS [Created],
[Limit1].[UpdatedBy] AS [UpdatedBy],
[Limit1].[Updated] AS [Updated],
[Limit1].[Employee_ID] AS [Employee_ID]
FROM ( SELECT TOP (2)
[Extent1].[ID] AS [ID],
[Extent1].[TimeEntriesXml] AS [TimeEntriesXml],
[Extent1].[ManagerID] AS [ManagerID],
[Extent1].[DivisionManagerID] AS [DivisionManagerID],
[Extent1].[CreatedBy] AS [CreatedBy],
[Extent1].[Created] AS [Created],
[Extent1].[UpdatedBy] AS [UpdatedBy],
[Extent1].[Updated] AS [Updated],
[Extent1].[Employee_ID] AS [Employee_ID],
1 AS [C1]
FROM [TimeCard].[TimeCardEntry] AS [Extent1]
WHERE [Extent1].[ID] = #p0
) AS [Limit1]',N'#p0 uniqueidentifier',#p0='10F3E723-4E12-48CD-8750-5922A1E42AA3'

Answer 1

EF is trying to declare Employee_ID in the database because it needs column for foreign key to Employee table. It cannot use your EmployeeID property and its columns as foreign key because it is declared as computed - foreign keys in EF must not be declared as computed or identity (it is not supported).
Solution for your model either requires abandoning navigation properties and work with IDs only (and loading related employees manually) or abandoning those computed columns - I can imagine that both options may be quite annoying.