title: how to use spring.jpa.hibernate.ddl-auto
body: <p>I currently have hibernate.ddl set:</p>
  
  <pre><code>spring.jpa.hibernate.ddl-auto = create-drop 
  </code></pre>
  
  <p>I don't to lose my data again and again...
  What value I can use Instead of deleting and creating the schema every time 
  Is there a way to update the existing one?<br>
  I was trying to use <strong>update</strong> in place of <strong>create-drop</strong> but it throws an exception:</p>
  
  <pre><code> [ERROR] Failed to execute goal org.springframework.boot:spring-boot-maven-plugin:1.3.3.RELEASE:run (default-cli) on project fno-connector-core: 
  An exception occurred while running. null: InvocationTargetException: 
  Failed to execute SQL script statement #1 of URL [file:/D:/..../classes/data.sql]: 
  insert into users (username, enabled, password, first_name, last_name, email) 
  values ('admin', true, '************', 'Flexera', 'Admin', 'aurovindosahu@*****.com'); 
  nested exception is java.sql.SQLIntegrityConstraintViolationException: Duplicate entry 'admin' for key 'PRIMARY'
  </code></pre>