public void AddForeignKeyConstraint <TForeignTableKey, TForeignTable>(
Table <TForeignTableKey, TForeignTable> foreignTable,
Expression <Func <TRow, TForeignTableKey> > foreignKeySelector)
{
var ourKeySelector = foreignKeySelector.Compile();
_constraintManager.RegisterInsertUpdateConstraint(ourRow =>
{
var key = ourKeySelector(ourRow);
var foreignRecordsAtOurKey = foreignTable._clusteredIndex.Seek(SeekTarget.From(key), Retrieval.Default);
if (!foreignRecordsAtOurKey.Any())
{
throw new Exception($"Key '{key}' does not exist in foreign table");
}
});
CreateIndex(foreignKeySelector);
foreignTable._constraintManager.RegisterDeleteConstraint(theirPrimaryKey =>
{
var index = _indexManager.FindIndex <TForeignTableKey, IIndex <TForeignTableKey, TRow> >(foreignKeySelector).Value;
var ourRecordsAtTheirKey = index.Seek(SeekTarget.From(theirPrimaryKey), Retrieval.Default);
if (ourRecordsAtTheirKey.Any())
{
throw new Exception($"Can't delete '{theirPrimaryKey}' as a foreign table refers to it");
}
});
}
public IEnumerable <TOut> QueryWithIndexSeek <TPredicateKey, TOut>(
Expression <Func <TRow, TPredicateKey> > indexSelector,
Func <TRow, TOut> select,
IEnumerable <TPredicateKey> fromKeys,
int?skip = null,
int?take = null,
bool reverse = false)
{
var index = _indexManager.FindIndex(indexSelector);
if (!index.HasValue)
{
throw new Exception($"No index registered for key: '{Expressions.GetMemberName(indexSelector)}'");
}
return(index.Value.Seek(SeekTarget.From(fromKeys), new Retrieval(skip, take, reverse))
.Select(select)
.ToArray()
.AsEnumerable());
}