/// <summary>
/// Retrieves an enumerable collection of all ReferentialConstraints in this SSDL/StoreItemCollection
/// </summary>
/// <param name="storeItemCollection">StoreItemCollection representing the SSDL</param>
/// <returns>The list of ReferentialConstraints.</returns>
public static IEnumerable <ReferentialConstraint> GetAllReferentialConstraints(this StoreItemCollection storeItemCollection)
{
var refConstraints = new List <ReferentialConstraint>();
foreach (AssociationType association in storeItemCollection.GetAllAssociations())
{
refConstraints.AddRange(association.ReferentialConstraints);
}
return(refConstraints);
}
// TODO: in order to properly identify this we may need to add custom annotations in the SSDL
/// <summary>
/// We can infer that something is a join table in the SSDL if:
/// 1. There are two associations originating from it
/// 2. The two ends on the table are *
/// 3. The other ends on the associations are 1
/// 4. The number of properties in the table is equal to the sum of all the key properties on the other ends of both associations
/// 5. All properties in the table are key properties
/// </summary>
/// <param name="entityType">The EntityType to test.</param>
/// <param name="store">The StoreItemCollection containing EntityType.</param>
/// <returns>true if the specified EntityType is a join table; otherwise, false.</returns>
public static bool IsJoinTable(this EntityType entityType, StoreItemCollection store)
{
var associations = store.GetAllAssociations().Where(a => a.IsAssociatedWithEntityType(entityType));
if (associations.Count() == 2)
{
var sumOfAllKeyProperties = 0;
var numEndsWithOneMultiplicity = 0;
foreach (AssociationType association in associations)
{
AssociationEndMember end1 = association.GetEnd1();
AssociationEndMember end2 = association.GetEnd2();
if ((end1.GetEntityType() == entityType) &&
(end1.RelationshipMultiplicity == RelationshipMultiplicity.Many) &&
(end2.RelationshipMultiplicity == RelationshipMultiplicity.One))
{
sumOfAllKeyProperties += end2.GetEntityType().GetKeyProperties().Count();
numEndsWithOneMultiplicity++;
}
else if ((end2.GetEntityType() == entityType) &&
(end2.RelationshipMultiplicity == RelationshipMultiplicity.Many) &&
(end1.RelationshipMultiplicity == RelationshipMultiplicity.One))
{
sumOfAllKeyProperties += end1.GetEntityType().GetKeyProperties().Count();
numEndsWithOneMultiplicity++;
}
}
int intersectCount = entityType.GetKeyProperties().Intersect(entityType.Properties).Count();
if (numEndsWithOneMultiplicity == 2 &&
entityType.GetKeyProperties().Count() == sumOfAllKeyProperties &&
entityType.GetKeyProperties().Count() == intersectCount &&
entityType.Properties.Count == intersectCount)
{
return(true);
}
}
return(false);
}
