// <summary>
// Creates an EntityKey for a principal entity based on the foreign key values contained
// in this entity. This implies that this entity is at the dependent end of the relationship.
// </summary>
// <param name="dependentEntry"> The EntityEntry for the dependent that contains the FK </param>
// <param name="constraint"> The constraint that describes this FK relationship </param>
// <param name="principalEntitySet"> The entity set at the principal end of the relationship </param>
// <param name="useOriginalValues"> If true then the key will be constructed from the original FK values </param>
// <returns> The key, or null if any value in the key is null </returns>
public static EntityKey CreateKeyFromForeignKeyValues(
EntityEntry dependentEntry, ReferentialConstraint constraint, EntitySet principalEntitySet, bool useOriginalValues)
{
// Build the key values. If any part of the key is null, then the entire key
// is considered null.
var dependentProps = constraint.ToProperties;
var numValues = dependentProps.Count;
if (numValues == 1)
{
var keyValue = useOriginalValues
? dependentEntry.GetOriginalEntityValue(dependentProps.First().Name)
: dependentEntry.GetCurrentEntityValue(dependentProps.First().Name);
return(keyValue == DBNull.Value ? null : new EntityKey(principalEntitySet, keyValue));
}
// Note that the properties in the principal entity set may be in a different order than
// they appear in the constraint. Therefore, we create name value mappings to ensure that
// the correct values are associated with the correct properties.
// Unfortunately, there is not way to call the public EntityKey constructor that takes pairs
// because the internal "object" constructor hides it. Even this doesn't work:
// new EntityKey(principalEntitySet, (IEnumerable<KeyValuePair<string, object>>)keyValues)
var keyNames = principalEntitySet.ElementType.KeyMemberNames;
Debug.Assert(keyNames.Length == numValues, "Number of entity set key names does not match constraint names");
var values = new object[numValues];
var principalProps = constraint.FromProperties;
for (var i = 0; i < numValues; i++)
{
var value = useOriginalValues
? dependentEntry.GetOriginalEntityValue(dependentProps[i].Name)
: dependentEntry.GetCurrentEntityValue(dependentProps[i].Name);
if (value == DBNull.Value)
{
return(null);
}
var keyIndex = Array.IndexOf(keyNames, principalProps[i].Name);
Debug.Assert(keyIndex >= 0 && keyIndex < numValues, "Could not find constraint prop name in entity set key names");
values[keyIndex] = value;
}
return(new EntityKey(principalEntitySet, values));
}
public static EntityKey CreateKeyFromForeignKeyValues(
EntityEntry dependentEntry,
ReferentialConstraint constraint,
EntitySet principalEntitySet,
bool useOriginalValues)
{
ReadOnlyMetadataCollection <EdmProperty> toProperties = constraint.ToProperties;
int count = toProperties.Count;
if (count == 1)
{
object singletonKeyValue = useOriginalValues ? dependentEntry.GetOriginalEntityValue(toProperties.First <EdmProperty>().Name) : dependentEntry.GetCurrentEntityValue(toProperties.First <EdmProperty>().Name);
if (singletonKeyValue != DBNull.Value)
{
return(new EntityKey((EntitySetBase)principalEntitySet, singletonKeyValue));
}
return((EntityKey)null);
}
string[] keyMemberNames = principalEntitySet.ElementType.KeyMemberNames;
object[] compositeKeyValues = new object[count];
ReadOnlyMetadataCollection <EdmProperty> fromProperties = constraint.FromProperties;
for (int index1 = 0; index1 < count; ++index1)
{
object obj = useOriginalValues ? dependentEntry.GetOriginalEntityValue(toProperties[index1].Name) : dependentEntry.GetCurrentEntityValue(toProperties[index1].Name);
if (obj == DBNull.Value)
{
return((EntityKey)null);
}
int index2 = Array.IndexOf <string>(keyMemberNames, fromProperties[index1].Name);
compositeKeyValues[index2] = obj;
}
return(new EntityKey((EntitySetBase)principalEntitySet, compositeKeyValues));
}
/// <summary>
/// Creates an EntityKey for a principal entity based on the foreign key values contained
/// in this entity. This implies that this entity is at the dependent end of the relationship.
/// </summary>
/// <param name="dependentEntry"> The EntityEntry for the dependent that contains the FK </param>
/// <param name="constraint"> The constraint that describes this FK relationship </param>
/// <param name="principalEntitySet"> The entity set at the principal end of the the relationship </param>
/// <param name="useOriginalValues"> If true then the key will be constructed from the original FK values </param>
/// <returns> The key, or null if any value in the key is null </returns>
public static EntityKey CreateKeyFromForeignKeyValues(
EntityEntry dependentEntry, ReferentialConstraint constraint, EntitySet principalEntitySet, bool useOriginalValues)
{
// Build the key values. If any part of the key is null, then the entire key
// is considered null.
var dependentProps = constraint.ToProperties;
var numValues = dependentProps.Count;
if (numValues == 1)
{
var keyValue = useOriginalValues
? dependentEntry.GetOriginalEntityValue(dependentProps.First().Name)
: dependentEntry.GetCurrentEntityValue(dependentProps.First().Name);
return keyValue == DBNull.Value ? null : new EntityKey(principalEntitySet, keyValue);
}
// Note that the properties in the principal entity set may be in a different order than
// they appear in the constraint. Therefore, we create name value mappings to ensure that
// the correct values are associated with the correct properties.
// Unfortunately, there is not way to call the public EntityKey constructor that takes pairs
// because the internal "object" constructor hides it. Even this doesn't work:
// new EntityKey(principalEntitySet, (IEnumerable<KeyValuePair<string, object>>)keyValues)
var keyNames = principalEntitySet.ElementType.KeyMemberNames;
Debug.Assert(keyNames.Length == numValues, "Number of entity set key names does not match constraint names");
var values = new object[numValues];
var principalProps = constraint.FromProperties;
for (var i = 0; i < numValues; i++)
{
var value = useOriginalValues
? dependentEntry.GetOriginalEntityValue(dependentProps[i].Name)
: dependentEntry.GetCurrentEntityValue(dependentProps[i].Name);
if (value == DBNull.Value)
{
return null;
}
var keyIndex = Array.IndexOf(keyNames, principalProps[i].Name);
Debug.Assert(keyIndex >= 0 && keyIndex < numValues, "Could not find constraint prop name in entity set key names");
values[keyIndex] = value;
}
return new EntityKey(principalEntitySet, values);
}
