Multiple databases | Docs

<!doctype html> <html lang="en"> <head> <title>Multiple databases | Docs | Ebean</title> <meta charset="utf-8"> <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no"> <link rel="shortcut icon" href="/images/favicon.ico"> <link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Roboto|Source+Sans+Pro|Ubuntu&display=swap"> <link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.1.0/css/all.css" integrity="sha384-lKuwvrZot6UHsBSfcMvOkWwlCMgc0TaWr+30HWe3a4ltaBwTZhyTEggF5tJv8tbt" crossorigin="anonymous"> <link rel="stylesheet" href="/css/reset3.css"> <link rel="stylesheet" href="/css/site3.css"> <link rel="stylesheet" href="/css/pygments3.css"> </head> <body> <div id="main"> <div id="banner"> <header> <nav id="top"> <h1 id="breadcrumb"> <a class="nav-logo" href="/"><img src="/images/logo-200.png" height="35"></a>  <a href="/docs">Documentation</a> / Multiple databases </h1> <ul> <li><a onclick="toggleTheme();" title="switch dark light theme"></a></li> </ul> </nav> </header> </div> <div class="grid grid-docs"> <aside> <nav class="side"> <ul> <li class="nav0 "> <a href="/docs/getting-started">Getting started</a> </li> <li class="nav0 "> <a href="/docs/intro">Introduction</a> </li> <li class="nav0 active"> <a class="active" href="/docs">Documentation</a> <ul> <li class="nav1 "> <a href="/docs/best-practice">Best practice</a> </li> <li class="nav1 "> <a href="/docs/query">Query</a> </li> <li class="nav1 "> <a href="/docs/persist">Persist</a> </li> <li class="nav1 "> <a href="/docs/transactions">Transactions</a> </li> <li class="nav1 "> <a href="/docs/mapping">Mapping</a> </li> <li class="nav1 "> <a href="/docs/ddl-generation">DDL & Migrations</a> </li> <li class="nav1 "> <a href="/docs/logging">Logging</a> </li> <li class="nav1 "> <a href="/docs/testing">Testing</a> </li> <li class="nav1 "> <a href="/docs/read-replicas">Read Replicas</a> </li> <li class="nav1 "> <a href="/docs/database">Database platforms</a> </li> <li class="nav1 active"> <a class="active" href="/docs/multi-database">Multiple databases</a> <ul class="nav"> <li > <a href="#model">Model constructor</a> </li> <li > <a href="#dbName">@DbName</a> </li> <li > <a href="#finder">Finder constructor</a> </li> <li > <a href="#register">Register</a> </li> </ul> </li> <li class="nav1 "> <a href="/docs/kotlin">Kotlin</a> </li> <li><a href="/docs/tuning">Tuning</a></li> <li class="nav1 "> <a href="/docs/features">Features</a> </li> </ul> </li> <li class="nav0 "> <a href="/support">Getting help</a> </li> <li class="nav0 "> <a target="_blank" href="/apidoc/13">API Javadoc</a> </li> <li class="nav0 "> <a href="/videos">Videos</a> </li> <li class="nav0 "> <a href="/docs/upgrading">Upgrading</a> </li> <li class="nav0 "> <a href="/releases">Releases</a> </li> </ul> </nav> </aside> <article> <form action="https://www.google.com/search" method="get" class="inline-form"> <input type="hidden" name="as_sitesearch" value="ebean.io"> <div id="page-search"> <div class="input-group"> <input class="frm" name="q" id="searchinput" type="text" placeholder="Search... (press 's' to focus)" data-placeholder-focus="Search... (use '↑', '↓' and '⏎' to select results)" data-placeholder-blur="Search... (press 's' to focus)" autocomplete="off"> <div class="input-group-btn"> <button class="frm" type="submit"></button> </div> </div> <div id="page-search-results" style="display: none;"> <ul id="search-results-container" class="search-results"><li class=" active"><a href="/docs" title="Docs">Docs Documentation </a></li><li class="">And 101 more...</li></ul> </div> </div> </form> When using multiple databases one database is known as the default database. We need to do 4 things for entity beans that should only be used on the non-default database(s). <h2 id="model">Model constructor</h2> Use the <code>io.ebean.Model</code> constructor that take the string name of the database that should be used. <ul class="code nav nav-tabs mytabs"> <li role="presentation" class="javaActive active"><a onclick="setLang('java');">java</a></li> <li role="presentation" class="kotlinActive"><a onclick="setLang('kt');">kotlin</a></li> </ul> <div class="code-java"> <div class="syntax java"><div class="highlight"><pre>... @DbName("other") @MappedSuperclass public abstract class OtherBaseDomain extends Model { public OtherBaseDomain() { super("other"); // "other" -> database name } ... } </pre></div> </div> </div> <div class="code-kt"> <div class="syntax kotlin"><div class="highlight"><pre>... @DbName("other") @MappedSuperclass open class OtherBaseDomain : Model("other") { // "other" -> database name ... } </pre></div> </div> </div> All entity beans that extend this model will use the named database when they <code>save()</code> and <code>delete()</code>. <h2 id="dbName">@DbName</h2> Put <code>@DbName</code> on a mapped superclass or individual entity beans. This is read by the querybean generator when generating the query beans so that queries for this entity bean type will execute using the named non-default database. <ul class="code nav nav-tabs mytabs"> <li role="presentation" class="javaActive active"><a onclick="setLang('java');">java</a></li> <li role="presentation" class="kotlinActive"><a onclick="setLang('kt');">kotlin</a></li> </ul> <div class="code-java"> <div class="syntax java"><div class="highlight"><pre>... @DbName("other") // "other" -> database name @MappedSuperclass public abstract class OtherBaseDomain extends Model { public OtherBaseDomain() { super("other"); // "other" -> database name } ... } </pre></div> </div> </div> <div class="code-kt"> <div class="syntax kotlin"><div class="highlight"><pre>... @DbName("other") // "other" -> database name @MappedSuperclass open class OtherBaseDomain : Model("other") { // "other" -> database name ... } </pre></div> </div> </div> For all entity beans extending <code>OtherBaseDomain</code> their query beans will now default to using the named database. <h2 id="finder">Finder constructor</h2> If using <code>io.ebean.Finder</code> we similarly use the constructor that takes the string name of the database that should be used. <ul class="code nav nav-tabs mytabs"> <li role="presentation" class="javaActive active"><a onclick="setLang('java');">java</a></li> <li role="presentation" class="kotlinActive"><a onclick="setLang('kt');">kotlin</a></li> </ul> <div class="code-java"> <div class="syntax java"><div class="highlight"><pre>... public class CustomerFinder extends Finder { public CustomerFinder() { super("other"); // "other" -> database name } ... } </pre></div> </div> </div> <div class="code-kt"> <div class="syntax kotlin"><div class="highlight"><pre>... open class CustomerFinder : Finder("other") { // "other" -> database name ... } </pre></div> </div> </div> Now using methods on CustomerFinder will default to using the named database. <h2 id="register">Register entity types</h2> We also need to register some entity types to the default database and some entity types to the other non default database(s). Note that from Ebean version 12.2.1 the querybean generator will generate code to register the entity bean types to the appropriate database. Create an implementation of ServerConfigProvider that registers the entity beans with the appropriate database based on the name. <div class="syntax java"><div class="highlight"><pre>public class RegisterDomainBeans implements ServerConfigProvider { private static final String OTHER = "other"; private static final String DB = "db"; @Override public void apply(ServerConfig serverConfig) { log.debug("register beans for {}", serverConfig.getName()); if (DB.equals(serverConfig.getName())) { // the default database serverConfig.addClass(DCustomer.class); serverConfig.addClass(DOrder.class); serverConfig.addClass(DProduct.class); ... } else if (OTHER.equals(serverConfig.getName())) { // second OTHER database serverConfig.setDefaultServer(false); serverConfig.addClass(OSales.class); serverConfig.addClass(OMarket.class); ... } } } </pre></div> </div> Add a service loader <code>src/main/resources/META-INF/services/io.ebean.config.ServerConfigProvider</code> file to specify our ServerConfigProvider implementation (e.g. RegisterDomainBeans). <nav class="next"> <a href="https://github.com/ebean-orm/website-source/blob/master/docs/multi-database/index.html"> Edit Page</a> <a href="/docs/tuning" class="btn btn-info">Next: Tuning</a> </nav> </article> </div> </div> <script src="https://code.jquery.com/jquery-3.4.1.slim.min.js" integrity="sha384-J6qa4849blE2+poT4WnyKhv5vZF5SrPo0iEjwBvKU7imGFAV0wwj1yYfoRSJoZ+n" crossorigin="anonymous"></script> <script src="/js/site3.js"></script> <script src="/js/search3.js"></script> <script async src="https://www.googletagmanager.com/gtag/js?id=UA-75181644-1"></script> <script> window.dataLayer = window.dataLayer || []; function gtag(){dataLayer.push(arguments);} gtag('js', new Date()); gtag('config', 'UA-75181644-1'); </script> </body> </html>

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Multiple databases | Docs | Ebean