private EntityMetaData DetermineJoinTable <ONE, MANY>() where ONE : class where MANY : class
{
try
{
EntityMetaData joinTableMD = entityMetaData.GetMeta4JoinEntity(
entityMetaData.GetMeta4Entity <ONE>(),
entityMetaData.GetMeta4Entity <MANY>());
if (joinTableMD == null)
{
throw new ArgumentException("Entity type unknown in repository.");
}
return(joinTableMD);
}
catch (Exception e)
{
throw e;
}
}
// For Insert: For the potential new situation: Outbound references: If fkKey is nullable AND contains nullvalues then allow else see function "NumberOfRecordsMatchesMultiplicity"
// Inbound references: no test needed.
// For Delete: For the potential new situation: Outbound references: First check for Cascade deletes, if so Cascade the deletion else always allow
// Inbound references: See functon "NumberOfRecordsMatchesMultiplicity4Delete"
// For Update: For the potential new situation: Outbound references: Same as Insert.
// Inbound references: Always allow
private async Task <Boolean> CheckInboundReferences(dynamic record)
{
EntityMetaData recordMD = entityMetaData.GetMeta4Entity(record);
if (recordMD == null)
{
throw new ArgumentException("Entity type unknown in repository.");
}
foreach (var inRefEntity in recordMD.inRefs)
{
foreach (var foreignKey in inRefEntity.outRefs) // foreignKey inRef---->----references---->record (= record to delete)
{
if (foreignKey.referredEntity != recordMD)
{
break; //only Inrefs to "me"
}
{ // now we have got all the inbound references.
if (!CheckMetaDataArguments(foreignKey))
{
return(false);
}
object[] KeyValues = property.GetPropertyValues(record, foreignKey.foreignKeyProjectionProperties);
if (NullAllowedAndPresent(foreignKey, KeyValues))
{
break;
}
int Referrers = await CountOccurencesOfEntityAsync(
inRefEntity.entity,
foreignKey.foreignKeyProperties,
KeyValues);
if (Referrers == 0)
{
break; // Nobody is referring to current record, so no need to check!
}
int recordCnt = await CountOccurencesOfEntityAsync(
foreignKey.referredEntity.entity,
foreignKey.foreignKeyProjectionProperties,
KeyValues);
if (!NumberOfRecordsMatchesMultiplicity4Delete(recordCnt, foreignKey.multiplicity))
{
return(false);
}
break;
}
}
}
return(true);
}
