public ReflectionTable(IRelationalDatabase database, IDatabaseDialect dialect, Type tableType)
{
Database = database ?? throw new ArgumentNullException(nameof(database));
Dialect = dialect ?? throw new ArgumentNullException(nameof(dialect));
InstanceType = tableType ?? throw new ArgumentNullException(nameof(tableType));
Name = Dialect.GetQualifiedNameOrDefault(database, InstanceType);
TypeProvider = new ReflectionTableTypeProvider(Dialect, InstanceType);
_columns = new Lazy <IReadOnlyList <IDatabaseColumn> >(LoadColumnList);
_checkLookup = new Lazy <IReadOnlyDictionary <Identifier, IDatabaseCheckConstraint> >(LoadChecks);
_uniqueKeyLookup = new Lazy <IReadOnlyDictionary <Identifier, IDatabaseKey> >(LoadUniqueKeys);
_indexLookup = new Lazy <IReadOnlyDictionary <Identifier, IDatabaseIndex> >(LoadIndexes);
_parentKeyLookup = new Lazy <IReadOnlyDictionary <Identifier, IDatabaseRelationalKey> >(LoadParentKeys);
_childKeys = new Lazy <IReadOnlyCollection <IDatabaseRelationalKey> >(LoadChildKeys);
_primaryKey = new Lazy <Option <IDatabaseKey> >(LoadPrimaryKey);
}
// TODO: see if it's possible to create a foreign key to a synonym in sql server
// this should be possible in oracle but not sure
private IReadOnlyDictionary <Identifier, IDatabaseRelationalKey> LoadParentKeys()
{
var result = new Dictionary <Identifier, IDatabaseRelationalKey>();
var parentKeys = TypeProvider.ParentKeys;
if (parentKeys.Empty())
{
return(result);
}
foreach (var declaredParentKey in parentKeys)
{
var fkColumns = declaredParentKey.Columns.Select(GetColumn).ToList();
var parentName = Dialect.GetQualifiedNameOrDefault(Database, declaredParentKey.TargetType);
var parentOption = Database.GetTable(parentName);
if (parentOption.IsNone.ConfigureAwait(false).GetAwaiter().GetResult())
{
throw new Exception("Could not find parent table with name: " + parentName.ToString());
}
var tmpOption = parentOption.ToOption().ConfigureAwait(false).GetAwaiter().GetResult();
var parent = tmpOption.MatchUnsafe(t => t, () => null !);
var parentTypeProvider = new ReflectionTableTypeProvider(Dialect, declaredParentKey.TargetType);
var parentInstance = parentTypeProvider.TableInstance;
var keyObject = declaredParentKey.KeySelector(parentInstance);
var parentKeyName = Dialect.GetAliasOrDefault(keyObject.Property !);
IDatabaseKey parentKey;
if (keyObject.KeyType == DatabaseKeyType.Primary)
{
// TODO: provide better error messaging, maybe to KeyNotFoundException too?
parentKey = parent.PrimaryKey
.Match(pk => pk, () => throw new Exception("Could not find matching parent key for foreign key."));
}
else if (keyObject.KeyType == DatabaseKeyType.Unique)
{
var uniqueKey = parent.UniqueKeys.FirstOrDefault(uk =>
uk.Name.Where(ukName => ukName.LocalName == parentKeyName).IsSome
);
parentKey = uniqueKey ?? throw new Exception("Could not find matching parent key for foreign key.");
}
else
{
throw new Exception("Cannot point a foreign key to a key that is not the primary key or a unique key."); // TODO: improve error messaging
}
// check that columns match up with parent key -- otherwise will fail
// TODO: don't assume that the FK is to a table -- could be to a synonym
// maybe change interface of Synonym<T> to be something like Synonym<Table<T>> or Synonym<Synonym<T>> -- could unwrap at runtime?
var childKeyName = Dialect.GetAliasOrDefault(declaredParentKey.Property !);
var childKey = new ReflectionForeignKey(childKeyName, parentKey, fkColumns);
var deleteAttr = Dialect.GetDialectAttribute <OnDeleteActionAttribute>(declaredParentKey.Property !);
var deleteAction = deleteAttr?.Action ?? ReferentialAction.NoAction;
var updateAttr = Dialect.GetDialectAttribute <OnUpdateActionAttribute>(declaredParentKey.Property !);
var updateAction = updateAttr?.Action ?? ReferentialAction.NoAction;
childKey.Name.IfSome(name => result[name.LocalName] = new ReflectionRelationalKey(Name, childKey, parent.Name, parentKey, deleteAction, updateAction));
}
return(result);
}
