I’m just starting out with EF CF (coming from PHP/MySQL land) and I’m hoping someone can help me understand what I’m doing wrong here.
Using the many great tutorials out there, I’ve created my model classes with relationships and the DB was being created and updated ok. But now I’m getting an issue with Cascade Delete.
From what I understand, this is caused when an entity can be deleted through Cascade Delete in more than way thus creating orphan records – is that right?
public class jbsEntity
{
[Timestamp]
public Byte[] TimeStamp { get; set; }
//public User CreatedBy { get; set; }
//public User UpdatedBy { get; set; }
}
public class Customer : jbsEntity
{
public int Id { get; set; }
public string Salutation { get; set; }
[Required, StringLength(128)]
public string FirstName { get; set; }
[Required, StringLength(128)]
public string LastName { get; set; }
public string BillingName { get; set; }
[Required, StringLength(128)]
public string Address { get; set; }
[Required, StringLength(128)]
public string Suburb { get; set; }
[Required, StringLength(4)]
public string Postcode { get; set; }
public string BillingAddress { get; set; }
public string BillingSuburb { get; set; }
public string BillingPostcode { get; set; }
public virtual List<Contact> Contacts { get; set; }
public virtual List<Residence> Residences { get; set; }
}
public class Residence : jbsEntity
{
public int Id { get; set; }
[Required, StringLength(128)]
public string Name { get; set; }
[Required, StringLength(128)]
public string Address { get; set; }
[Required, StringLength(128)]
public string Suburb { get; set; }
[Required, StringLength(4)]
public string Postcode { get; set; }
public bool Active { get; set; }
public string AccessInstructions { get; set; }
public string ServiceFrequency { get; set; }
public string RegularServiceCost { get; set; }
[Required]
public int CustomerId { get; set; }
public virtual Customer Customer { get; set; }
public virtual List<Contact> Contacts { get; set; }
public virtual List<Pool> Pools { get; set; }
public virtual List<Job> Jobs { get; set; }
public virtual List<Image> Images { get; set; }
}
public class Pool : jbsEntity
{
public int Id { get; set; }
[Required, StringLength(128)]
public string Name { get; set; }
[Required, StringLength(128)]
public string Size { get; set; }
public string AccessInstructions { get; set; }
public string SurfcaceType { get; set; }
public bool Indoor { get; set; }
public decimal TargetPH { get; set; }
public decimal TargetIron { get; set; }
public decimal TargetCopper { get; set; }
public decimal TargetCalcium { get; set; }
public decimal TargetChlorine { get; set; }
public decimal TargetAlkaline { get; set; }
public decimal TargetStabiliser { get; set; }
[Required]
public int ResidenceId { get; set; }
public virtual Residence Residence { get; set; }
public virtual List<JobService> JobServices { get; set; }
public virtual List<Image> Images { get; set; }
}
public class Equipment : jbsEntity
{
public int Id { get; set; }
[Required, StringLength(128)]
public string Name { get; set; }
public string Description { get; set; }
public DateTime Installed { get; set; }
public DateTime WarrantyExpiration { get; set; }
public string Status { get; set; }
[Required]
public int PoolId { get; set; }
public virtual Pool Pool { get; set; }
public virtual List<Image> Images { get; set; }
}
public class Contact : jbsEntity
{
public int Id { get; set; }
public string Salutation { get; set; }
[Required, StringLength(128)]
public string FirstName { get; set; }
[Required, StringLength(128)]
public string LastName { get; set; }
public string Email { get; set; }
public string Mobile { get; set; }
public string Phone { get; set; }
}
public class Image : jbsEntity
{
public int Id { get; set; }
public string FileName { get; set; }
public string FilePath { get; set; }
public string MimeType { get; set; }
}
public class Job : jbsEntity
{
public int Id { get; set; }
public string Name { get; set; }
public string Description { get; set; }
public string InvoiceNumber { get; set; }
public string Comments { get; set; }
public string CompletionNotes { get; set; }
public string DpscActionRequired { get; set; }
public string WorkPerformed { get; set; }
public string NextCallInstruction { get; set; }
public bool ServiceComplete { get; set; }
public DateTime DueDate { get; set; }
public DateTime ScheduledDate { get; set; }
public DateTime CompletionDate { get; set; }
[Required]
public int ResidenceId { get; set; }
public virtual Residence Residence { get; set; }
public virtual List<JobService> JobServices { get; set; }
public virtual List<Image> Images { get; set; }
}
public class JobService : jbsEntity
{
public int Id { get; set; }
public string Name { get; set; }
public bool SkimSurface { get; set; }
public bool BrushWalls { get; set; }
public bool Vacuum { get; set; }
public bool BackwashRinse { get; set; }
public bool EmptyBaskets { get; set; }
public bool CleanElectrodes { get; set; }
public bool BalanceWater { get; set; }
public bool AddedAcid { get; set; }
public bool AddedClarifier { get; set; }
public bool SwimClearOnsite { get; set; }
public decimal PH { get; set; }
public decimal Iron { get; set; }
public decimal Copper { get; set; }
public decimal Calcium { get; set; }
public decimal Chlorine { get; set; }
public decimal Alkaline { get; set; }
public decimal Stabiliser { get; set; }
[Required]
public int JobId { get; set; }
public virtual Job Job { get; set; }
[Required]
public int PoolId { get; set; }
public virtual Pool Pool { get; set; }
public virtual List<Image> Images { get; set; }
}
public class User : jbsEntity
{
public int Id { get; set; }
[Required]
public string UserName { get; set; }
[Required]
public string FirstName { get; set; }
[Required]
public string LastName { get; set; }
[Required]
public string Password { get; set; }
[Required, Compare("Password")]
public string ComparePassword { get; set; }
}
and I get this error:
{"Introducing FOREIGN KEY constraint 'Pool_Residence' on table 'Pools' may cause cycles or multiple cascade paths. Specify ON DELETE NO ACTION or ON UPDATE NO ACTION, or modify other FOREIGN KEY constraints.\r\nCould not create constraint. See previous errors."}
I think the relationships causing the issue are:
Customer -> Residences -> Pools
Job -> JobServices
Residence -> Jobs
Pools -> JobServices
Can anyone help me understand what I’m doing wrong and how I can work around it? Any other suggestions welcome as well!
Thanks in advance.
Actually you are not doing anything wrong but SQL Server doesn’t like to handle the multiple cascade delete paths. There are actually two delete paths from
ResidencetoPool.Residence->Job->JobService->PoolIn your model all of the foreign key columns are non-nullable. Hence EF tries to create FKs with cascade deletes.
To avoid the problem make one of the FKs nullable and handle the deletion of child entities through an alternate mechanism such as a Stored Procedure, Trigger, Through code.