From 61f876a345d8005e66fbd0c08628285494e47d09 Mon Sep 17 00:00:00 2001
From: Matt Hicks <matt@outr.com>
Date: Mon, 2 Sep 2024 10:16:30 -0500
Subject: [PATCH] Materialized work in progress

---
 .gitignore                                    |  5 +-
 core/src/main/scala/lightdb/Query.scala       |  2 +
 .../scala/lightdb/collection/Collection.scala | 26 ++++-----
 .../scala/lightdb/doc/DocumentModel.scala     |  3 +
 .../scala/lightdb/doc/MaterializedModel.scala | 25 ++++++++
 .../main/scala/lightdb/store/MapStore.scala   |  2 +
 core/src/main/scala/lightdb/store/Store.scala |  2 +
 .../lightdb/store/split/SplitStore.scala      |  4 +-
 .../trigger/BasicCollectionTrigger.scala      | 33 +++++++++++
 .../test/scala/spec/AbstractBasicSpec.scala   | 57 +++++++++++++++----
 .../scala/lightdb/halodb/HaloDBStore.scala    |  2 +
 .../scala/lightdb/lucene/LuceneStore.scala    |  2 +
 .../main/scala/lightdb/mapdb/MapDBStore.scala |  2 +
 .../main/scala/lightdb/redis/RedisStore.scala |  3 +
 .../scala/lightdb/rocksdb/RocksDBStore.scala  |  2 +
 sql/src/main/scala/lightdb/sql/SQLStore.scala |  2 +
 16 files changed, 147 insertions(+), 25 deletions(-)
 create mode 100644 core/src/main/scala/lightdb/doc/MaterializedModel.scala
 create mode 100644 core/src/main/scala/lightdb/trigger/BasicCollectionTrigger.scala

diff --git a/.gitignore b/.gitignore
index c09f2e58..7641d269 100644
--- a/.gitignore
+++ b/.gitignore
@@ -11,4 +11,7 @@ benchmark/data/
 /backup/
 backup.zip
 db/
-backups/
\ No newline at end of file
+backups/
+metals.sbt
+derby.log
+*report-*.json
\ No newline at end of file
diff --git a/core/src/main/scala/lightdb/Query.scala b/core/src/main/scala/lightdb/Query.scala
index 0478b016..d46cb5e6 100644
--- a/core/src/main/scala/lightdb/Query.scala
+++ b/core/src/main/scala/lightdb/Query.scala
@@ -110,6 +110,8 @@ case class Query[Doc <: Document[Doc], Model <: DocumentModel[Doc]](collection:
     }
   }
 
+  def iterator(implicit transaction: Transaction[Doc]): Iterator[Doc] = search.docs.iterator
+
   def toList(implicit transaction: Transaction[Doc]): List[Doc] = search.docs.list
 
   def first(implicit transaction: Transaction[Doc]): Option[Doc] = search.docs.iterator.nextOption()
diff --git a/core/src/main/scala/lightdb/collection/Collection.scala b/core/src/main/scala/lightdb/collection/Collection.scala
index 9c90ed7b..df1376ca 100644
--- a/core/src/main/scala/lightdb/collection/Collection.scala
+++ b/core/src/main/scala/lightdb/collection/Collection.scala
@@ -41,6 +41,9 @@ case class Collection[Doc <: Document[Doc], Model <: DocumentModel[Doc]](name: S
       case _ => // Can't do validation
     }
 
+    // Give the Model a chance to initialize
+    model.init(this)
+
     // Verify the data is in-sync
     verify()
   }
@@ -163,14 +166,14 @@ case class Collection[Doc <: Document[Doc], Model <: DocumentModel[Doc]](name: S
   }
 
   def insert(doc: Doc)(implicit transaction: Transaction[Doc]): Doc = {
-    store.insert(doc)
     trigger.insert(doc)
+    store.insert(doc)
     doc
   }
 
   def upsert(doc: Doc)(implicit transaction: Transaction[Doc]): Doc = {
-    store.upsert(doc)
     trigger.upsert(doc)
+    store.upsert(doc)
     doc
   }
 
@@ -178,6 +181,8 @@ case class Collection[Doc <: Document[Doc], Model <: DocumentModel[Doc]](name: S
 
   def upsert(docs: Seq[Doc])(implicit transaction: Transaction[Doc]): Seq[Doc] = docs.map(upsert)
 
+  def exists(id: Id[Doc])(implicit transaction: Transaction[Doc]): Boolean = store.exists(id)
+
   def get[V](f: Model => (UniqueIndex[Doc, V], V))(implicit transaction: Transaction[Doc]): Option[Doc] = {
     val (field, value) = f(model)
     store.get(field, value)
@@ -226,17 +231,13 @@ case class Collection[Doc <: Document[Doc], Model <: DocumentModel[Doc]](name: S
 
   def delete[V](f: Model => (UniqueIndex[Doc, V], V))(implicit transaction: Transaction[Doc]): Boolean = {
     val (field, value) = f(model)
-    try {
-      store.delete(field, value)
-    } finally {
-      trigger.delete(field, value)
-    }
+    trigger.delete(field, value)
+    store.delete(field, value)
   }
 
-  def delete(id: Id[Doc])(implicit transaction: Transaction[Doc], ev: Model <:< DocumentModel[_]): Boolean = try {
-    store.delete(ev(model)._id.asInstanceOf[UniqueIndex[Doc, Id[Doc]]], id)
-  } finally {
+  def delete(id: Id[Doc])(implicit transaction: Transaction[Doc], ev: Model <:< DocumentModel[_]): Boolean = {
     trigger.delete(ev(model)._id.asInstanceOf[UniqueIndex[Doc, Id[Doc]]], id)
+    store.delete(ev(model)._id.asInstanceOf[UniqueIndex[Doc, Id[Doc]]], id)
   }
 
   def count(implicit transaction: Transaction[Doc]): Int = store.count
@@ -245,10 +246,9 @@ case class Collection[Doc <: Document[Doc], Model <: DocumentModel[Doc]](name: S
 
   lazy val query: Query[Doc, Model] = Query(this)
 
-  def truncate()(implicit transaction: Transaction[Doc]): Int = try {
-    store.truncate()
-  } finally {
+  def truncate()(implicit transaction: Transaction[Doc]): Int = {
     trigger.truncate()
+    store.truncate()
   }
 
   def dispose(): Unit = try {
diff --git a/core/src/main/scala/lightdb/doc/DocumentModel.scala b/core/src/main/scala/lightdb/doc/DocumentModel.scala
index 3f7e1141..9fd332fa 100644
--- a/core/src/main/scala/lightdb/doc/DocumentModel.scala
+++ b/core/src/main/scala/lightdb/doc/DocumentModel.scala
@@ -1,6 +1,7 @@
 package lightdb.doc
 
 import fabric.rw._
+import lightdb.collection.Collection
 import lightdb.filter.FilterBuilder
 import lightdb.{Field, Id, Indexed, Tokenized, Unique, UniqueIndex}
 
@@ -15,6 +16,8 @@ trait DocumentModel[Doc <: Document[Doc]] {
 
   def id(value: String = Unique()): Id[Doc] = Id(value)
 
+  def init[Model <: DocumentModel[Doc]](collection: Collection[Doc, Model]): Unit = {}
+
   type F[V] = Field[Doc, V]
   type I[V] = Indexed[Doc, V]
   type U[V] = UniqueIndex[Doc, V]
diff --git a/core/src/main/scala/lightdb/doc/MaterializedModel.scala b/core/src/main/scala/lightdb/doc/MaterializedModel.scala
new file mode 100644
index 00000000..d54c6329
--- /dev/null
+++ b/core/src/main/scala/lightdb/doc/MaterializedModel.scala
@@ -0,0 +1,25 @@
+package lightdb.doc
+
+import lightdb.collection.Collection
+import lightdb.transaction.Transaction
+import lightdb.trigger.BasicCollectionTrigger
+
+trait MaterializedModel[Doc <: Document[Doc], MaterialDoc <: Document[MaterialDoc], MaterialModel <: DocumentModel[MaterialDoc]] extends DocumentModel[Doc] { mm =>
+  def materialCollection: Collection[MaterialDoc, MaterialModel]
+
+  protected def adding(doc: MaterialDoc)(implicit transaction: Transaction[MaterialDoc]): Unit
+  protected def modifying(oldDoc: MaterialDoc, newDoc: MaterialDoc)(implicit transaction: Transaction[MaterialDoc]): Unit
+  protected def removing(doc: MaterialDoc)(implicit transaction: Transaction[MaterialDoc]): Unit
+
+  override def init[Model <: DocumentModel[Doc]](collection: Collection[Doc, Model]): Unit = {
+    super.init(collection)
+
+    materialCollection.trigger += new BasicCollectionTrigger[MaterialDoc, MaterialModel] {
+      override def collection: Collection[MaterialDoc, MaterialModel] = materialCollection
+
+      override protected def adding(doc: MaterialDoc)(implicit transaction: Transaction[MaterialDoc]): Unit = mm.adding(doc)
+      override protected def modifying(oldDoc: MaterialDoc, newDoc: MaterialDoc)(implicit transaction: Transaction[MaterialDoc]): Unit = mm.modifying(oldDoc, newDoc)
+      override protected def removing(doc: MaterialDoc)(implicit transaction: Transaction[MaterialDoc]): Unit = mm.removing(doc)
+    }
+  }
+}
diff --git a/core/src/main/scala/lightdb/store/MapStore.scala b/core/src/main/scala/lightdb/store/MapStore.scala
index ecbbc903..2fffc3ab 100644
--- a/core/src/main/scala/lightdb/store/MapStore.scala
+++ b/core/src/main/scala/lightdb/store/MapStore.scala
@@ -24,6 +24,8 @@ class MapStore[Doc <: Document[Doc], Model <: DocumentModel[Doc]](val storeMode:
     map += id(doc) -> doc
   }
 
+  override def exists(id: Id[Doc])(implicit transaction: Transaction[Doc]): Boolean = map.contains(id)
+
   override def get[V](field: UniqueIndex[Doc, V], value: V)(implicit transaction: Transaction[Doc]): Option[Doc] = {
     if (field == idField) {
       map.get(value.asInstanceOf[Id[Doc]])
diff --git a/core/src/main/scala/lightdb/store/Store.scala b/core/src/main/scala/lightdb/store/Store.scala
index 7bb1b689..3bd57a49 100644
--- a/core/src/main/scala/lightdb/store/Store.scala
+++ b/core/src/main/scala/lightdb/store/Store.scala
@@ -47,6 +47,8 @@ abstract class Store[Doc <: Document[Doc], Model <: DocumentModel[Doc]] {
 
   def upsert(doc: Doc)(implicit transaction: Transaction[Doc]): Unit
 
+  def exists(id: Id[Doc])(implicit transaction: Transaction[Doc]): Boolean
+
   def get[V](field: UniqueIndex[Doc, V], value: V)(implicit transaction: Transaction[Doc]): Option[Doc]
 
   def delete[V](field: UniqueIndex[Doc, V], value: V)(implicit transaction: Transaction[Doc]): Boolean
diff --git a/core/src/main/scala/lightdb/store/split/SplitStore.scala b/core/src/main/scala/lightdb/store/split/SplitStore.scala
index a97ee388..1f583aa1 100644
--- a/core/src/main/scala/lightdb/store/split/SplitStore.scala
+++ b/core/src/main/scala/lightdb/store/split/SplitStore.scala
@@ -6,7 +6,7 @@ import lightdb.doc.{Document, DocumentModel}
 import lightdb.materialized.MaterializedAggregate
 import lightdb.store.{Conversion, Store, StoreMode}
 import lightdb.transaction.{Transaction, TransactionKey}
-import lightdb.{Field, Query, SearchResults, UniqueIndex}
+import lightdb.{Field, Id, Query, SearchResults, UniqueIndex}
 
 import scala.language.implicitConversions
 
@@ -34,6 +34,8 @@ case class SplitStore[Doc <: Document[Doc], Model <: DocumentModel[Doc]](storage
     searching.upsert(doc)
   }
 
+  override def exists(id: Id[Doc])(implicit transaction: Transaction[Doc]): Boolean = storage.exists(id)
+
   override def get[V](field: UniqueIndex[Doc, V], value: V)(implicit transaction: Transaction[Doc]): Option[Doc] = {
     storage.get(field, value)
   }
diff --git a/core/src/main/scala/lightdb/trigger/BasicCollectionTrigger.scala b/core/src/main/scala/lightdb/trigger/BasicCollectionTrigger.scala
new file mode 100644
index 00000000..855e5cab
--- /dev/null
+++ b/core/src/main/scala/lightdb/trigger/BasicCollectionTrigger.scala
@@ -0,0 +1,33 @@
+package lightdb.trigger
+
+import lightdb.UniqueIndex
+import lightdb.collection.Collection
+import lightdb.doc.{Document, DocumentModel}
+import lightdb.transaction.Transaction
+
+trait BasicCollectionTrigger[Doc <: Document[Doc], Model <: DocumentModel[Doc]] extends CollectionTrigger[Doc] {
+  def collection: Collection[Doc, Model]
+
+  protected def adding(doc: Doc)(implicit transaction: Transaction[Doc]): Unit
+
+  protected def modifying(oldDoc: Doc, newDoc: Doc)(implicit transaction: Transaction[Doc]): Unit
+
+  protected def removing(doc: Doc)(implicit transaction: Transaction[Doc]): Unit
+
+  override final def insert(doc: Doc)(implicit transaction: Transaction[Doc]): Unit = adding(doc)
+
+  override final def upsert(doc: Doc)(implicit transaction: Transaction[Doc]): Unit = {
+    collection.get(doc._id) match {
+      case Some(current) => modifying(current, doc)
+      case None => adding(doc)
+    }
+  }
+
+  override final def delete[V](index: UniqueIndex[Doc, V], value: V)(implicit transaction: Transaction[Doc]): Unit = {
+    collection.query.filter(_ => index === value).iterator.foreach(removing)
+  }
+
+  override final def truncate(): Unit = collection.transaction { implicit transaction =>
+    collection.iterator.foreach(removing)
+  }
+}
diff --git a/core/src/test/scala/spec/AbstractBasicSpec.scala b/core/src/test/scala/spec/AbstractBasicSpec.scala
index dd48dddc..4782158b 100644
--- a/core/src/test/scala/spec/AbstractBasicSpec.scala
+++ b/core/src/test/scala/spec/AbstractBasicSpec.scala
@@ -3,10 +3,11 @@ package spec
 import fabric.rw._
 import lightdb.backup.{DatabaseBackup, DatabaseRestore}
 import lightdb.collection.Collection
-import lightdb.doc.{Document, DocumentModel, JsonConversion}
+import lightdb.doc.{Document, DocumentModel, JsonConversion, MaterializedModel}
 import lightdb.feature.DBFeatureKey
 import lightdb.filter._
 import lightdb.store.StoreManager
+import lightdb.transaction.Transaction
 import lightdb.upgrade.DatabaseUpgrade
 import lightdb.{Field, Id, LightDB, Sort, StoredValue}
 import org.scalatest.matchers.should.Matchers
@@ -102,6 +103,9 @@ abstract class AbstractBasicSpec extends AnyWordSpec with Matchers { spec =>
         ages should be(Set(101, 42, 89, 102, 53, 13, 2, 22, 12, 81, 35, 63, 99, 23, 30, 4, 21, 33, 11, 72, 15, 62))
       }
     }
+    /*"verify the AgeLinks is properly updated" in {
+      db.ageLinks.t.get(AgeLinks.id(30)).map(_.people) should be(Some(List(Id("yuri"), Id("wyatt"), Id("tori"))))
+    }*/
     "query with aggregate functions" in {
       if (aggregationSupported) {
         db.people.transaction { implicit transaction =>
@@ -285,10 +289,10 @@ abstract class AbstractBasicSpec extends AnyWordSpec with Matchers { spec =>
     }
     "insert a lot more names" in {
       db.people.transaction { implicit transaction =>
-        val p = (1 to 100_000).toList.map { index =>
+        val p = (1 to 1_000).toList.map { index =>
           Person(
             name = s"Unique Snowflake $index",
-            age = if (index > 10_000) 0 else index,
+            age = if (index > 100) 0 else index,
             city = Some(City("Robotland")),
             nicknames = Set("robot", s"sf$index")
           )
@@ -298,7 +302,7 @@ abstract class AbstractBasicSpec extends AnyWordSpec with Matchers { spec =>
     }
     "verify the correct number of people exist in the database" in {
       db.people.transaction { implicit transaction =>
-        db.people.count should be(100_024)
+        db.people.count should be(1_024)
       }
     }
     "verify the correct count in query total" in {
@@ -311,8 +315,8 @@ abstract class AbstractBasicSpec extends AnyWordSpec with Matchers { spec =>
           .search
           .docs
         results.list.length should be(100)
-        results.total should be(Some(100_000))
-        results.remaining should be(Some(100_000))
+        results.total should be(Some(1_000))
+        results.remaining should be(Some(1_000))
       }
     }
     "verify the correct count in query total with offset" in {
@@ -325,13 +329,13 @@ abstract class AbstractBasicSpec extends AnyWordSpec with Matchers { spec =>
           .search
           .docs
         results.list.length should be(100)
-        results.total should be(Some(100_000))
-        results.remaining should be(Some(99_900))
+        results.total should be(Some(1_000))
+        results.remaining should be(Some(900))
       }
     }
     "truncate the collection" in {
       db.people.transaction { implicit transaction =>
-        db.people.truncate() should be(100_024)
+        db.people.truncate() should be(1_024)
       }
     }
     "verify the collection is empty" in {
@@ -370,6 +374,8 @@ abstract class AbstractBasicSpec extends AnyWordSpec with Matchers { spec =>
     val startTime: StoredValue[Long] = stored[Long]("startTime", -1L)
 
     val people: Collection[Person, Person.type] = collection(Person)
+    // TODO: Revisit this - performance is currently awful and transaction state causes overlapping dirty data
+//    val ageLinks: Collection[AgeLinks, AgeLinks.type] = collection(AgeLinks)
 
     override def storeManager: StoreManager = spec.storeManager
 
@@ -383,7 +389,7 @@ abstract class AbstractBasicSpec extends AnyWordSpec with Matchers { spec =>
                     _id: Id[Person] = Person.id()) extends Document[Person]
 
   object Person extends DocumentModel[Person] with JsonConversion[Person] {
-    implicit val rw: RW[Person] = RW.gen
+    override implicit val rw: RW[Person] = RW.gen
 
     val name: I[String] = field.index("name", _.name)
     val age: I[Int] = field.index("age", _.age)
@@ -398,6 +404,37 @@ abstract class AbstractBasicSpec extends AnyWordSpec with Matchers { spec =>
     implicit val rw: RW[City] = RW.gen
   }
 
+  /*case class AgeLinks(age: Int, people: List[Id[Person]]) extends Document[AgeLinks] {
+    lazy val _id: Id[AgeLinks] = AgeLinks.id(age)
+  }
+
+  object AgeLinks extends MaterializedModel[AgeLinks, Person, Person.type] with JsonConversion[AgeLinks] {
+    override implicit val rw: RW[AgeLinks] = RW.gen
+
+    val age: F[Int] = field("age", _.age)
+    val people: F[List[Id[Person]]] = field("people", _.people)
+
+    override def materialCollection: Collection[Person, Person.type] = db.people
+
+    def id(age: Int): Id[AgeLinks] = Id(age.toString)
+
+    override protected def adding(doc: Person)(implicit transaction: Transaction[Person]): Unit = db.ageLinks.t.modify(AgeLinks.id(doc.age)) {
+      case Some(links) => Some(links.copy(people = (doc._id :: links.people).distinct))
+      case None => Some(AgeLinks(doc.age, List(doc._id)))
+    }
+    override protected def modifying(oldDoc: Person, newDoc: Person)(implicit transaction: Transaction[Person]): Unit = adding(newDoc)
+    override protected def removing(doc: Person)(implicit transaction: Transaction[Person]): Unit = db.ageLinks.t.modify(AgeLinks.id(doc.age)) {
+      case Some(links) =>
+        val l = links.copy(people = links.people.filterNot(_ == doc._id))
+        if (l.people.isEmpty) {
+          None
+        } else {
+          Some(l)
+        }
+      case None => None
+    }
+  }*/
+
   object InitialSetupUpgrade extends DatabaseUpgrade {
     override def applyToNew: Boolean = true
 
diff --git a/halodb/src/main/scala/lightdb/halodb/HaloDBStore.scala b/halodb/src/main/scala/lightdb/halodb/HaloDBStore.scala
index a4eedfbe..685536f2 100644
--- a/halodb/src/main/scala/lightdb/halodb/HaloDBStore.scala
+++ b/halodb/src/main/scala/lightdb/halodb/HaloDBStore.scala
@@ -48,6 +48,8 @@ class HaloDBStore[Doc <: Document[Doc], Model <: DocumentModel[Doc]](directory:
     instance.put(id(doc).bytes, JsonFormatter.Compact(json).getBytes("UTF-8"))
   }
 
+  override def exists(id: Id[Doc])(implicit transaction: Transaction[Doc]): Boolean = get(idField, id).nonEmpty
+
   override def get[V](field: UniqueIndex[Doc, V], value: V)(implicit transaction: Transaction[Doc]): Option[Doc] = {
     if (field == idField) {
       Option(instance.get(value.asInstanceOf[Id[Doc]].bytes)).map(bytes2Doc)
diff --git a/lucene/src/main/scala/lightdb/lucene/LuceneStore.scala b/lucene/src/main/scala/lightdb/lucene/LuceneStore.scala
index 865b38f1..5bb4d645 100644
--- a/lucene/src/main/scala/lightdb/lucene/LuceneStore.scala
+++ b/lucene/src/main/scala/lightdb/lucene/LuceneStore.scala
@@ -114,6 +114,8 @@ class LuceneStore[Doc <: Document[Doc], Model <: DocumentModel[Doc]](directory:
     }
   }
 
+  override def exists(id: Id[Doc])(implicit transaction: Transaction[Doc]): Boolean = get(idField, id).nonEmpty
+
   override def get[V](field: UniqueIndex[Doc, V], value: V)
                      (implicit transaction: Transaction[Doc]): Option[Doc] = {
     val filter = Filter.Equals(field, value)
diff --git a/mapdb/src/main/scala/lightdb/mapdb/MapDBStore.scala b/mapdb/src/main/scala/lightdb/mapdb/MapDBStore.scala
index d586586b..142788ef 100644
--- a/mapdb/src/main/scala/lightdb/mapdb/MapDBStore.scala
+++ b/mapdb/src/main/scala/lightdb/mapdb/MapDBStore.scala
@@ -36,6 +36,8 @@ class MapDBStore[Doc <: Document[Doc], Model <: DocumentModel[Doc]](directory: O
 
   override def upsert(doc: Doc)(implicit transaction: Transaction[Doc]): Unit = map.put(doc._id.value, toString(doc))
 
+  override def exists(id: Id[Doc])(implicit transaction: Transaction[Doc]): Boolean = map.containsKey(id.value)
+
   override def get[V](field: UniqueIndex[Doc, V], value: V)
                      (implicit transaction: Transaction[Doc]): Option[Doc] = {
     if (field == idField) {
diff --git a/redis/src/main/scala/lightdb/redis/RedisStore.scala b/redis/src/main/scala/lightdb/redis/RedisStore.scala
index 666c83fb..7123d499 100644
--- a/redis/src/main/scala/lightdb/redis/RedisStore.scala
+++ b/redis/src/main/scala/lightdb/redis/RedisStore.scala
@@ -40,6 +40,9 @@ class RedisStore[Doc <: Document[Doc], Model <: DocumentModel[Doc]](val storeMod
   override def upsert(doc: Doc)(implicit transaction: Transaction[Doc]): Unit =
     getInstance.hset(collection.name, doc._id.value, toString(doc))
 
+  override def exists(id: Id[Doc])(implicit transaction: Transaction[Doc]): Boolean =
+    getInstance.hexists(collection.name, id.value)
+
   override def get[V](field: UniqueIndex[Doc, V], value: V)
                      (implicit transaction: Transaction[Doc]): Option[Doc] = {
     if (field == idField) {
diff --git a/rocksdb/src/main/scala/lightdb/rocksdb/RocksDBStore.scala b/rocksdb/src/main/scala/lightdb/rocksdb/RocksDBStore.scala
index e3570ca4..fad41fbc 100644
--- a/rocksdb/src/main/scala/lightdb/rocksdb/RocksDBStore.scala
+++ b/rocksdb/src/main/scala/lightdb/rocksdb/RocksDBStore.scala
@@ -35,6 +35,8 @@ class RocksDBStore[Doc <: Document[Doc], Model <: DocumentModel[Doc]](directory:
     db.put(doc._id.bytes, JsonFormatter.Compact(json).getBytes("UTF-8"))
   }
 
+  override def exists(id: Id[Doc])(implicit transaction: Transaction[Doc]): Boolean = db.keyExists(id.bytes)
+
   override def get[V](field: UniqueIndex[Doc, V], value: V)
                      (implicit transaction: Transaction[Doc]): Option[Doc] = {
     if (field == idField) {
diff --git a/sql/src/main/scala/lightdb/sql/SQLStore.scala b/sql/src/main/scala/lightdb/sql/SQLStore.scala
index b75fed1d..0835b885 100644
--- a/sql/src/main/scala/lightdb/sql/SQLStore.scala
+++ b/sql/src/main/scala/lightdb/sql/SQLStore.scala
@@ -164,6 +164,8 @@ abstract class SQLStore[Doc <: Document[Doc], Model <: DocumentModel[Doc]] exten
     }
   }
 
+  override def exists(id: Id[Doc])(implicit transaction: Transaction[Doc]): Boolean = get(idField, id).nonEmpty
+
   override def get[V](field: UniqueIndex[Doc, V], value: V)
                      (implicit transaction: Transaction[Doc]): Option[Doc] = {
     val state = getState