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<!doctype html> <html lang="en"> <head> <title>DB Migrations | Intro | 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><span class="sep"> / </span><a href="/docs/intro/">Introduction</a><span class="sep"> / </span><span class="last">DB migrations</span> </h1> <ul> <li><a onclick="toggleTheme();" title="switch dark light theme"><i class="fas fa-adjust"></i></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 active"> <a class="active" href="/docs/intro">Introduction</a> <ul> <li class="nav1 "> <a href="/docs/intro/database">Database & DB</a> </li> <li class="nav1 "> <a href="/docs/intro/configuration">Configuration</a> </li> <li class="nav1 "> <a href="/docs/intro/first-entity">First entity</a> </li> <li class="nav1 "> <a href="/docs/intro/queries">Queries</a> </li> <li class="nav1 "> <a href="/docs/intro/logging">Logging</a> </li> <li class="nav1 active"> <a class="active" href="/docs/intro/db-migrations">DB Migrations</a> <ul class="nav nav-scroll"> <li > <a href="#generate">Generate migrations</a> </li> <li > <a href="#run">Run migrations</a> </li> </ul> </li> <li class="nav1 "> <a href="/docs/intro/limitations">Limitations</a> </li> <li class="nav1 "> <a href="/docs/trouble-shooting">Trouble shooting</a> </li> </ul> </li> <li class="nav0 "> <a href="/docs">Documentation</a> </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... 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(press 's' to focus)" autocomplete="off"> <div class="input-group-btn"> <button class="frm" type="submit"><i class="fas fa-search"></i></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"><span style="color:#777;">Docs</span> Documentation </a></li><li class=""><small style="color:#999;">And 101 more...</small></li></ul> </div> </div> </form> <h2>DB Migrations</h2> <p> Ebean has built in support for generating DB migrations and running them </p> <h2 id="generate">Generating DB Migrations</h2> <p> Note that we can use <a href="/docs/getting-started/cli-tool">ebeaninit</a> to add <em>GenerateDbMigration</em> (the code below) to your project. </p> <div class="code-java"> <p> In <code>src/test/java</code> add the code below to generate migrations. </p> </div> <div class="code-kt"> <p> In <code>src/test/kotlin</code> add the code below to generate migrations. </p> </div> <p> To generate a DB migration we run this main method. The migration DDL for the given platform will be generated based on the changes to the model (e.g. alter table add column etc). </p> <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><span></span><span class="kn">package</span> <span class="nn">main</span><span class="o">;</span> <span class="kn">import</span> <span class="nn">io.ebean.annotation.Platform</span><span class="o">;</span> <span class="kn">import</span> <span class="nn">io.ebean.dbmigration.DbMigration</span><span class="o">;</span> <span class="kn">import</span> <span class="nn">java.io.IOException</span><span class="o">;</span> <span class="kd">public</span> <span class="kd">class</span> <span class="nc">GenerateDbMigration</span> <span class="o">{</span> <span class="cm">/**</span> <span class="cm"> * Generate the DDL for the next DB migration.</span> <span class="cm"> */</span> <span class="kd">public</span> <span class="kd">static</span> <span class="kt">void</span> <span class="nf">main</span><span class="o">(</span><span class="n">String</span><span class="o">[]</span> <span class="n">args</span><span class="o">)</span> <span class="kd">throws</span> <span class="n">IOException</span> <span class="o">{</span> <span class="n">DbMigration</span> <span class="n">dbMigration</span> <span class="o">=</span> <span class="n">DbMigration</span><span class="o">.</span><span class="na">create</span><span class="o">();</span> <span class="n">dbMigration</span><span class="o">.</span><span class="na">setPlatform</span><span class="o">(</span><span class="n">Platform</span><span class="o">.</span><span class="na">POSTGRES</span><span class="o">);</span> <span class="n">dbMigration</span><span class="o">.</span><span class="na">generateMigration</span><span class="o">();</span> <span class="o">}</span> <span class="o">}</span> </pre></div> </div> </div> <div class="code-kt"> <div class="syntax kotlin"><div class="highlight"><pre><span></span><span class="k">package</span> <span class="nn">main</span> <span class="k">import</span> <span class="nn">io.ebean.annotation.Platform</span> <span class="k">import</span> <span class="nn">io.ebean.dbmigration.DbMigration</span> <span class="cm">/**</span> <span class="cm"> * Generate the DDL for the next DB migration.</span> <span class="cm"> */</span> <span class="k">fun</span> <span class="nf">main</span><span class="p">(</span><span class="n">args</span> <span class="p">:</span> <span class="n">Array</span><span class="p"><!</span><span class="n">String</span><span class="p">>)</span> <span class="p">{</span> <span class="c1">// requires jvmTarget 1.8</span> <span class="k">val</span> <span class="py">dbMigration</span> <span class="p">=</span> <span class="n">DbMigration</span><span class="p">.</span><span class="n">create</span><span class="p">()</span> <span class="n">dbMigration</span><span class="p">.</span><span class="n">setPlatform</span><span class="p">(</span><span class="n">Platform</span><span class="p">.</span><span class="n">POSTGRES</span><span class="p">)</span> <span class="n">dbMigration</span><span class="p">.</span><span class="n">generateMigration</span><span class="p">()</span> <span class="p">}</span> </pre></div> </div> </div> <p> We run this manually when we have completed some work and consider it ready to be released. </p> <p> Running the generation starts Ebean in offline mode, performs a DIFF of the model and generates the migration DDL script. </p> <h2 id="run">Running Migration</h2> <p> To run the migration using the built in migration runner, set <code>ebean.migration.run</code> to true. </p> <h5>In application.yaml</h5> <div class="syntax yml"><div class="highlight"><pre><span></span><span class="c1">## run migrations when the Ebean starts</span> <span class="nt">ebean</span><span class="p">:</span> <span class="nt">migration</span><span class="p">:</span> <span class="nt">run</span><span class="p">:</span> <span class="l l-Scalar l-Scalar-Plain">true</span> </pre></div> </div> <p> With <code>ebean.migration.run=true</code> then when the Ebean starts it will look at the migrations and run any that need to be run. The migration runner will by default create a table called <code>db_migration</code> that holds the meta data about the migrations that have been run and inserts into this table when migrations are successfully executed. </p> <nav class="next"> <p class="edit-page"> <a href="https://github.com/ebean-orm/website-source/blob/master/docs/intro/db-migrations/index.html"><i class="fab fa-github"></i> Edit Page</a> </p> <p class="next"> <a href="/docs/intro/limitations" class="btn btn-info">Next: Limitations</a> </p> </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>