How to make hbm2ddl schemaExport to log schema to

问题:

A quote from persistence.xml:

<persistence-unit name="test" transaction-type="RESOURCE_LOCAL">
    <properties>
        <property name="hibernate.archive.autodetection" value="class" />
        <property name="hibernate.show_sql" value="true" />
        <property name="hibernate.format_sql" value="true" />
        <property name="hibernate.hbm2ddl.auto" value="create" />
        ...
    </properties>
</persistence-unit>

This is what I see in log output:

Sep 30, 2010 12:03:43 PM org.hibernate.tool.hbm2ddl.SchemaExport execute
INFO: Running hbm2ddl schema export
Sep 30, 2010 12:03:43 PM org.hibernate.tool.hbm2ddl.SchemaExport execute
INFO: exporting generated schema to database
Sep 30, 2010 12:03:43 PM org.hibernate.tool.hbm2ddl.SchemaExport execute
INFO: schema export complete

But I don't see the schema (SQL) exported itself. How to get this information out of Hibernate (3.5.6-Final)?

回答1:

Activate the logging of the org.hibernate.tool.hbm2ddl category to DEBUG.

---

Update: Here is a simplified logback.xml (I'm using logback as logging backend):

<configuration scan="true">

  <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
    <layout class="ch.qos.logback.classic.PatternLayout">
      <Pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</Pattern>
    </layout>
  </appender>

  <!-- ### log just the SQL ### -->
  <logger name="org.hibernate.SQL" level="DEBUG"/>

  <!-- ### log JDBC bind parameters ### -->
  <logger name="org.hibernate.type" level="TRACE"/>

  <logger name="org.hibernate.tool.hbm2ddl" level="DEBUG"/>

  <root level="ERROR">
    <appender-ref ref="STDOUT"/>
  </root>
</configuration>

Adapt it if you are using log4j (you'll find working configuration here on SO).

回答2:

Just in case you stumble upon this using Spring Boot. You can configure the following in your application.yml:

spring.jpa:
  hibernate.ddl-auto: create-drop
logging.level:               
  org.hibernate.tool.hbm2ddl: DEBUG
  org.hibernate.SQL: DEBUG   
  org.hibernate.type: TRACE  

回答3:

Here is a simplified log4j.xml configuration.

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
<log4j:configuration>
    <appender name="CA" class="org.apache.log4j.ConsoleAppender">
        <layout class="org.apache.log4j.PatternLayout">
            <param name="ConversionPattern" value="%-4r [%t] %-5p %c %x - %m%n"/>
        </layout>
    </appender>
    <!-- ### log just the SQL ### -->
    <logger name="org.hibernate.SQL">
        <level value="DEBUG" />
    </logger>
    <!-- ### log JDBC bind parameters ### -->
    <logger name="org.hibernate.type">
        <level value="TRACE" />
    </logger>
    <!-- ### log Hibernate model to schema tool ### -->
    <logger name="org.hibernate.tool.hbm2ddl">
        <level value="DEBUG" />
    </logger>
    <root>
        <level value="WARN"/>
        <appender-ref ref="CA"/>
    </root>
</log4j:configuration>