title: tables are truncated with "spring.jpa.hibernate.ddl-auto" to validate
body: <p>NB: Spring Boot 2.1.10 + Spring Cloud Greenwich.SR3</p>
  
  <p>I have two Spring Data JPA services accessing the same external database (which is MySQL) and sharing a common domain:</p>
  
  <pre><code>@Entity
  @Data
  public class Person {
      @Id @GeneratedValue(strategy = GenerationType.IDENTITY)
      private Long id;
      @Column(name = "first_name") @NotNull
      private String firstname;
      private LocalDate birth;
      private Integer votes = 0;
  }
  </code></pre>
  
  <p>In the first service (producer) I added a data.sql for samples insertion:</p>
  
  <pre><code>insert into person(first_name) values ('foobar');
  insert into person(first_name) values ('scoubidou');
  </code></pre>
  
  <p>And the following properties:</p>
  
  <pre><code>spring.jpa.hibernate.ddl-auto=create-drop
  spring.datasource.initialization-mode=always
  </code></pre>
  
  <p>In the second service (consumer) I just want to use the schema without modifying it at startup, so I used those properties:</p>
  
  <pre><code>spring.jpa.hibernate.ddl-auto=validate
  spring.datasource.initialization-mode=never
  </code></pre>
  
  <p>When starting the producer, the DB schema is created and filled with sample entities.
  But when I start the consumer, then the entities table is truncated.
  Does anybody know how the table would gat emptied and how to avoid it, please?</p>