CINXE.COM

<!DOCTYPE html> <html lang="en"><head><script type="text/javascript" src="https://www.googletagmanager.com/gtm.js?id=GTM-MX6DBN9" async="async"></script><script type="text/javascript" src="/static/hash-o6oemknr/js/gtm.js"></script><meta charset="utf-8"/><meta http-equiv="X-UA-Compatible" content="IE=edge"/><meta name="viewport" content="width=device-width, height=device-height, initial-scale=1, user-scalable=no"/><meta name="generator" content="made with love by dartdoc"/><meta name="description" content="objectbox library API docs, for the Dart programming language."/><title>objectbox library - Dart API</title><link rel="canonical" href="https://pub.dev/documentation/objectbox/latest/objectbox/objectbox-library.html"/><link rel="preconnect" href="https://fonts.gstatic.com"/><link rel="stylesheet" href="https://fonts.googleapis.com/css2?family=Roboto+Mono:ital,wght@0,300;0,400;0,500;0,700;1,400&display=swap"/><link rel="stylesheet" href="https://fonts.googleapis.com/css2?family=Material+Symbols+Outlined:opsz,wght,FILL,GRAD@24,400,0,0"/><link rel="stylesheet" href="/static/hash-o6oemknr/css/dartdoc.css"/><link rel="icon" href="/favicon.ico?hash=nk4nss8c7444fg0chird9erqef2vkhb8"/></head><body class="light-theme" data-base-href="../" data-using-base-href="false"><noscript><iframe src="https://www.googletagmanager.com/ns.html?id=GTM-MX6DBN9" height="0" width="0" style="display:none;visibility:hidden"></iframe></noscript><div id="overlay-under-drawer"></div><header id="title">menu<a class="hidden-xs" href="/"><img src="/static/hash-o6oemknr/img/dart-logo.svg" alt="" width="30" height="30" role="presentation" style="height: 30px; margin-right: 1em;"/></a><ol class="breadcrumbs gt-separated dark hidden-xs"><li><a href="/packages/objectbox">objectbox package</a></li><li><a href="../index.html">documentation</a></li><li class="self-crumb">objectbox.dart</li></ol><div class="self-name">objectbox.dart</div><form class="search navbar-right" role="search"><input id="search-box" class="form-control typeahead" type="text" placeholder="Loading search..." autocomplete="off"/></form><div id="theme-button" class="toggle" title="Toggle brightness"><label for="theme"><input id="theme" type="checkbox" value="light-theme"/>dark_modelight_mode</label></div></header><main><div id="dartdoc-main-content" class="main-content" data-above-sidebar="" data-below-sidebar="objectbox/objectbox-library-sidebar.html"> <div> <h1> objectbox library </h1> </div> <div class="desc markdown markdown-body"> ObjectBox for Dart is a standalone database storing Dart objects locally, with strong ACID semantics. Read the <a href="https://docs.objectbox.io/getting-started" rel="ugc nofollow">Getting Started</a> guide. </div> <div class="summary offset-anchor" id="classes"> <h2>Classes</h2> <dl> <dt id="Admin"> <a href="../objectbox/Admin-class.html">Admin</a> </dt> <dd> ObjectBox Admin allows you to explore the database in a regular web browser. </dd> <dt id="Backlink"> <a href="../objectbox/Backlink-class.html">Backlink</a> </dt> <dd> Backlink annotation specifies a link in a reverse direction of another relation. </dd> <dt id="Box"> <a href="../objectbox/Box-class.html">Box</a><T> </dt> <dd> A Box instance gives you access to objects of a particular type. You get Box instances via <a href="../objectbox/Store/box.html">Store.box()</a> or <a href="../objectbox/Box-class.html">Box(Store)</a>. </dd> <dt id="Condition"> <a href="../objectbox/Condition-class.html">Condition</a><EntityT> </dt> <dd> A <a href="../objectbox/Query-class.html">Query</a> condition base class. </dd> <dt id="DebugFlags"> <a href="../objectbox/DebugFlags-class.html">DebugFlags</a> </dt> <dd> Passed as <code>debugFlags</code> when calling <a href="../objectbox/Store/Store.html">Store.new</a> to enable debug options. </dd> <dt id="Entity"> <a href="../objectbox/Entity-class.html">Entity</a> </dt> <dd> Entity annotation is used on a class to let ObjectBox know it should store it - making the class a "persistable Entity". </dd> <dt id="HnswFlags"> <a href="../objectbox/HnswFlags-class.html">HnswFlags</a> </dt> <dd> Flags as a part of the <a href="../objectbox/HnswIndex-class.html">HnswIndex</a> configuration. </dd> <dt id="HnswIndex"> <a href="../objectbox/HnswIndex-class.html">HnswIndex</a> </dt> <dd> See <a href="../objectbox/HnswIndex/HnswIndex.html">HnswIndex.new</a>. </dd> <dt id="Id"> <a href="../objectbox/Id-class.html">Id</a> </dt> <dd> Annotation Id can be used to specify an entity ID property if it's named anything else then "id" (case insensitive). </dd> <dt id="IdWithScore"> <a href="../objectbox/IdWithScore-class.html">IdWithScore</a> </dt> <dd> Wraps the ID of a matching object and a score when using <a href="../objectbox/Query/findIdsWithScores.html">Query.findIdsWithScores</a>. </dd> <dt id="Index"> <a href="../objectbox/Index-class.html">Index</a> </dt> <dd> Specifies that the property should be indexed. </dd> <dt id="ObjectWithScore"> <a href="../objectbox/ObjectWithScore-class.html">ObjectWithScore</a><T> </dt> <dd> Wraps a matching object and a score when using <a href="../objectbox/Query/findWithScores.html">Query.findWithScores</a>. </dd> <dt id="Order"> <a href="../objectbox/Order-class.html">Order</a> </dt> <dd> Groups query order flags. </dd> <dt id="Property"> <a href="../objectbox/Property-class.html">Property</a> </dt> <dd> Use to (optionally) annotate a field to explicitly configure some details about how a field is stored in the database. </dd> <dt id="PropertyQuery"> <a href="../objectbox/PropertyQuery-class.html">PropertyQuery</a><T> </dt> <dd> Property query base. </dd> <dt id="Query"> <a href="../objectbox/Query-class.html">Query</a><T> </dt> <dd> A repeatable Query returning the latest matching Objects. </dd> <dt id="QueryBacklinkToMany"> <a href="../objectbox/QueryBacklinkToMany-class.html">QueryBacklinkToMany</a><Source, Target> </dt> <dd> </dd> <dt id="QueryBooleanProperty"> <a href="../objectbox/QueryBooleanProperty-class.html">QueryBooleanProperty</a><EntityT> </dt> <dd> </dd> <dt id="QueryBuilder"> <a href="../objectbox/QueryBuilder-class.html">QueryBuilder</a><T> </dt> <dd> Query builder allows creating reusable queries. </dd> <dt id="QueryByteVectorProperty"> <a href="../objectbox/QueryByteVectorProperty-class.html">QueryByteVectorProperty</a><EntityT> </dt> <dd> </dd> <dt id="QueryDateNanoProperty"> <a href="../objectbox/QueryDateNanoProperty-class.html">QueryDateNanoProperty</a><EntityT> </dt> <dd> This wraps <a href="../objectbox/QueryIntegerProperty-class.html">QueryIntegerProperty</a> for <a href="https://api.dart.dev/stable/3.5.4/dart-core/DateTime-class.html" rel="ugc">DateTime</a> properties annotated with <code>@Property(type: PropertyType.dateNano)</code> to avoid having to manually convert to nanoseconds (<a href="https://api.dart.dev/stable/3.5.4/dart-core/DateTime/microsecondsSinceEpoch.html" rel="ugc">DateTime.microsecondsSinceEpoch</a> <code>* 1000</code>) when creating query conditions. </dd> <dt id="QueryDateProperty"> <a href="../objectbox/QueryDateProperty-class.html">QueryDateProperty</a><EntityT> </dt> <dd> This wraps <a href="../objectbox/QueryIntegerProperty-class.html">QueryIntegerProperty</a> for <a href="https://api.dart.dev/stable/3.5.4/dart-core/DateTime-class.html" rel="ugc">DateTime</a> properties to avoid having to manually convert to <a href="https://api.dart.dev/stable/3.5.4/dart-core/DateTime/millisecondsSinceEpoch.html" rel="ugc">DateTime.millisecondsSinceEpoch</a> when creating query conditions. </dd> <dt id="QueryDoubleProperty"> <a href="../objectbox/QueryDoubleProperty-class.html">QueryDoubleProperty</a><EntityT> </dt> <dd> </dd> <dt id="QueryDoubleVectorProperty"> <a href="../objectbox/QueryDoubleVectorProperty-class.html">QueryDoubleVectorProperty</a><EntityT> </dt> <dd> For double vectors greater and less queries are supported on elements of the vector (e.g. "has element greater"). </dd> <dt id="QueryHnswProperty"> <a href="../objectbox/QueryHnswProperty-class.html">QueryHnswProperty</a><EntityT> </dt> <dd> Provides extra conditions for float vector properties with an <a href="../objectbox/HnswIndex-class.html">HnswIndex</a>. </dd> <dt id="QueryIntegerProperty"> <a href="../objectbox/QueryIntegerProperty-class.html">QueryIntegerProperty</a><EntityT> </dt> <dd> </dd> <dt id="QueryIntegerVectorProperty"> <a href="../objectbox/QueryIntegerVectorProperty-class.html">QueryIntegerVectorProperty</a><EntityT> </dt> <dd> For integer vectors (excluding <a href="../objectbox/QueryByteVectorProperty-class.html">QueryByteVectorProperty</a>) greater, less and equal are supported on elements of the vector (e.g. "has element greater"). </dd> <dt id="QueryProperty"> <a href="../objectbox/QueryProperty-class.html">QueryProperty</a><EntityT, DartType> </dt> <dd> The QueryProperty types allow users to build query conditions on a property. </dd> <dt id="QueryRelationToMany"> <a href="../objectbox/QueryRelationToMany-class.html">QueryRelationToMany</a><Source, Target> </dt> <dd> </dd> <dt id="QueryRelationToOne"> <a href="../objectbox/QueryRelationToOne-class.html">QueryRelationToOne</a><Source, Target> </dt> <dd> </dd> <dt id="QueryStringProperty"> <a href="../objectbox/QueryStringProperty-class.html">QueryStringProperty</a><EntityT> </dt> <dd> </dd> <dt id="QueryStringVectorProperty"> <a href="../objectbox/QueryStringVectorProperty-class.html">QueryStringVectorProperty</a><EntityT> </dt> <dd> </dd> <dt id="Store"> <a href="../objectbox/Store-class.html">Store</a> </dt> <dd> Represents an ObjectBox database and works together with <a href="../objectbox/Box-class.html">Box</a> to allow getting and putting. </dd> <dt id="Sync"> <a href="../objectbox/Sync-class.html">Sync</a> </dt> <dd> <a href="https://objectbox.io/sync/" rel="ugc nofollow">ObjectBox Sync</a> makes data available and synchronized across devices, online and offline. </dd> <dt id="SyncChange"> <a href="../objectbox/SyncChange-class.html">SyncChange</a> </dt> <dd> Sync incoming data event. </dd> <dt id="SyncClient"> <a href="../objectbox/SyncClient-class.html">SyncClient</a> </dt> <dd> Sync client is used to connect to an ObjectBox sync server. Use through <a href="../objectbox/Sync-class.html">Sync</a>. </dd> <dt id="SyncCredentials"> <a href="../objectbox/SyncCredentials-class.html">SyncCredentials</a> </dt> <dd> Credentials used to authenticate a sync client against a server. </dd> <dt id="ToMany"> <a href="../objectbox/ToMany-class.html">ToMany</a><EntityT> </dt> <dd> A to-many relation of an entity that references multiple objects of a "target" entity <code>EntityT</code>. </dd> <dt id="ToOne"> <a href="../objectbox/ToOne-class.html">ToOne</a><EntityT> </dt> <dd> A to-one relation of an entity that references one object of a "target" entity <code>EntityT</code>. </dd> <dt id="Transient"> <a href="../objectbox/Transient-class.html">Transient</a> </dt> <dd> Transient annotation marks fields that should not be stored in the database. </dd> <dt id="Unique"> <a href="../objectbox/Unique-class.html">Unique</a> </dt> <dd> Enforces that the value of a property is unique among all objects in a box before an object can be put. </dd> <dt id="Version"> <a href="../objectbox/Version-class.html">Version</a> </dt> <dd> Wrapper for a semantic version information. </dd> </dl> </div> <div class="summary offset-anchor" id="enums"> <h2>Enums</h2> <dl> <dt id="ConflictStrategy"> <a href="../objectbox/ConflictStrategy.html">ConflictStrategy</a> </dt> <dd> Used with <a href="../objectbox/Unique-class.html">Unique</a> to specify the conflict resolution strategy. </dd> <dt id="IndexType"> <a href="../objectbox/IndexType.html">IndexType</a> </dt> <dd> IndexType can be used to change what type ObjectBox uses when indexing a property. </dd> <dt id="PropertyType"> <a href="../objectbox/PropertyType.html">PropertyType</a> </dt> <dd> Use with <a href="../objectbox/Property/type.html">Property.type</a>. </dd> <dt id="PutMode"> <a href="../objectbox/PutMode.html">PutMode</a> </dt> <dd> Box put (write) mode. </dd> <dt id="SyncConnectionEvent"> <a href="../objectbox/SyncConnectionEvent.html">SyncConnectionEvent</a> </dt> <dd> Connection state change event. </dd> <dt id="SyncLoginEvent"> <a href="../objectbox/SyncLoginEvent.html">SyncLoginEvent</a> </dt> <dd> Login state change event. </dd> <dt id="SyncRequestUpdatesMode"> <a href="../objectbox/SyncRequestUpdatesMode.html">SyncRequestUpdatesMode</a> </dt> <dd> Configuration of how <a href="../objectbox/SyncClient-class.html">SyncClient</a> fetches remote updates from the server. </dd> <dt id="SyncState"> <a href="../objectbox/SyncState.html">SyncState</a> </dt> <dd> Current state of the <a href="../objectbox/SyncClient-class.html">SyncClient</a>. </dd> <dt id="TxMode"> <a href="../objectbox/TxMode.html">TxMode</a> </dt> <dd> Configure transaction mode. Used with <a href="../objectbox/Store/runInTransaction.html">Store.runInTransaction()</a>. </dd> <dt id="VectorDistanceType"> <a href="../objectbox/VectorDistanceType.html">VectorDistanceType</a> </dt> <dd> The vector distance algorithm used by an <a href="../objectbox/HnswIndex-class.html">HnswIndex</a> (vector search). </dd> </dl> </div> <div class="summary offset-anchor" id="extensions"> <h2>Extensions</h2> <dl> <dt id="DoublePropertyQuery"> <a href="../objectbox/DoublePropertyQuery.html">DoublePropertyQuery</a> on <a href="../objectbox/PropertyQuery-class.html">PropertyQuery</a><<a href="https://api.dart.dev/stable/3.5.4/dart-core/double-class.html">double</a>> </dt> <dd> "Property query" for a double field. Created by <a href="../objectbox/Query/property.html">Query.property()</a>. </dd> <dt id="IntegerPropertyQuery"> <a href="../objectbox/IntegerPropertyQuery.html">IntegerPropertyQuery</a> on <a href="../objectbox/PropertyQuery-class.html">PropertyQuery</a><<a href="https://api.dart.dev/stable/3.5.4/dart-core/int-class.html">int</a>> </dt> <dd> "Property query" for an integer field. Created by <a href="../objectbox/Query/property.html">Query.property()</a>. </dd> <dt id="ObservableStore"> <a href="../objectbox/ObservableStore.html">ObservableStore</a> on <a href="../objectbox/Store-class.html">Store</a> </dt> <dd> StreamController implementation inspired by the sample controller sample at: <a href="https://dart.dev/articles/libraries/creating-streams#honoring-the-pause-state" rel="ugc">https://dart.dev/articles/libraries/creating-streams#honoring-the-pause-state</a> <a href="https://dart.dev/articles/libraries/code/stream_controller.dart" rel="ugc">https://dart.dev/articles/libraries/code/stream_controller.dart</a> </dd> <dt id="QueryParamBool"> <a href="../objectbox/QueryParamBool.html">QueryParamBool</a> on QueryParam<<a href="https://api.dart.dev/stable/3.5.4/dart-core/bool-class.html">bool</a>> </dt> <dd> QueryParam for boolean properties </dd> <dt id="QueryParamBytes"> <a href="../objectbox/QueryParamBytes.html">QueryParamBytes</a> on QueryParam<<a href="https://api.dart.dev/stable/3.5.4/dart-core/List-class.html">List</a><<a href="https://api.dart.dev/stable/3.5.4/dart-core/int-class.html">int</a>>> </dt> <dd> QueryParam for byte vector properties </dd> <dt id="QueryParamDouble"> <a href="../objectbox/QueryParamDouble.html">QueryParamDouble</a> on QueryParam<<a href="https://api.dart.dev/stable/3.5.4/dart-core/double-class.html">double</a>> </dt> <dd> QueryParam for double properties </dd> <dt id="QueryParamInt"> <a href="../objectbox/QueryParamInt.html">QueryParamInt</a> on QueryParam<<a href="https://api.dart.dev/stable/3.5.4/dart-core/int-class.html">int</a>> </dt> <dd> QueryParam for int properties </dd> <dt id="QueryParamString"> <a href="../objectbox/QueryParamString.html">QueryParamString</a> on QueryParam<<a href="https://api.dart.dev/stable/3.5.4/dart-core/String-class.html">String</a>> </dt> <dd> QueryParam for string properties </dd> <dt id="QuerySetParam"> <a href="../objectbox/QuerySetParam.html">QuerySetParam</a> on <a href="../objectbox/Query-class.html">Query</a> </dt> <dd> Adds capabilities to set query parameters </dd> <dt id="StringPropertyQuery"> <a href="../objectbox/StringPropertyQuery.html">StringPropertyQuery</a> on <a href="../objectbox/PropertyQuery-class.html">PropertyQuery</a><<a href="https://api.dart.dev/stable/3.5.4/dart-core/String-class.html">String</a>> </dt> <dd> "Property query" for a string field. Created by <a href="../objectbox/Query/property.html">Query.property()</a>. </dd> </dl> </div> <div class="summary offset-anchor" id="exceptions"> <h2>Exceptions / Errors</h2> <dl> <dt id="DbFileCorruptException"> <a href="../objectbox/DbFileCorruptException-class.html">DbFileCorruptException</a> </dt> <dd> Errors were detected in a database file, e.g. illegal values or structural inconsistencies. </dd> <dt id="DbFullException"> <a href="../objectbox/DbFullException-class.html">DbFullException</a> </dt> <dd> Thrown when applying a transaction (e.g. putting an object) would exceed the <code>maxDBSizeInKB</code> configured when calling <a href="../objectbox/Store/Store.html">Store.new</a>. </dd> <dt id="DbMaxDataSizeExceededException"> <a href="../objectbox/DbMaxDataSizeExceededException-class.html">DbMaxDataSizeExceededException</a> </dt> <dd> Thrown when applying a transaction would exceed the <code>maxDataSizeInKByte</code> configured when calling <a href="../objectbox/Store/Store.html">Store.new</a>. </dd> <dt id="DbMaxReadersExceededException"> <a href="../objectbox/DbMaxReadersExceededException-class.html">DbMaxReadersExceededException</a> </dt> <dd> Thrown when the maximum amount of readers (read transactions) was exceeded. </dd> <dt id="DbPagesCorruptException"> <a href="../objectbox/DbPagesCorruptException-class.html">DbPagesCorruptException</a> </dt> <dd> Errors related to pages were detected in a database file, e.g. bad page refs outside of the file. </dd> <dt id="DbShutdownException"> <a href="../objectbox/DbShutdownException-class.html">DbShutdownException</a> </dt> <dd> Thrown when an error occurred that requires the store to be closed. </dd> <dt id="NonUniqueResultException"> <a href="../objectbox/NonUniqueResultException-class.html">NonUniqueResultException</a> </dt> <dd> Thrown if <code>Query.findUnique()</code> is called, but the query matches more than one object. </dd> <dt id="NumericOverflowException"> <a href="../objectbox/NumericOverflowException-class.html">NumericOverflowException</a> </dt> <dd> Thrown if a property query aggregate function (e.g. <code>sum()</code>) can not compute a result due to a number type overflowing. </dd> <dt id="ObjectBoxException"> <a href="../objectbox/ObjectBoxException-class.html">ObjectBoxException</a> </dt> <dd> ObjectBox database exception. </dd> <dt id="SchemaException"> <a href="../objectbox/SchemaException-class.html">SchemaException</a> </dt> <dd> Thrown when there is an error with the data schema (data model). </dd> <dt id="StorageException"> <a href="../objectbox/StorageException-class.html">StorageException</a> </dt> <dd> ObjectBox database exception with an OBX_ERROR code. </dd> <dt id="UniqueViolationException"> <a href="../objectbox/UniqueViolationException-class.html">UniqueViolationException</a> </dt> <dd> A unique constraint would have been violated by this database operation. </dd> </dl> </div> </div><div id="dartdoc-sidebar-left" class="sidebar sidebar-offcanvas-left"><header id="header-search-sidebar" class="hidden-l"><form class="search-sidebar" role="search"><input id="search-sidebar" class="form-control typeahead" type="text" placeholder="Loading search..." autocomplete="off"/></form></header><ol id="sidebar-nav" class="breadcrumbs gt-separated dark hidden-l"><li><a href="/packages/objectbox">objectbox package</a></li><li><a href="../index.html">documentation</a></li><li class="self-crumb">objectbox.dart</li></ol>  <h5>objectbox package</h5> <ol> <li class="section-title">Libraries</li> <li><a href="../objectbox_internal/objectbox_internal-library.html">internal</a></li> <li><a href="../objectbox/objectbox-library.html">objectbox</a></li> </ol> <div id="dartdoc-sidebar-left-content"></div></div><div id="dartdoc-sidebar-right" class="sidebar sidebar-offcanvas-right"> <h5>objectbox library</h5> </div></main><footer>objectbox 4.0.3</footer><script src="/static/hash-o6oemknr/dartdoc/resources/highlight.pack.js"></script><script src="/static/hash-o6oemknr/dartdoc/resources/docs.dart.js"></script></body></html>