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Make it foolproof (until nature invents a better fool) 

git-svn-id: https://svn.jboss.org/repos/hibernate/trunk/Hibernate3/doc@7650 1b8cb986-b30d-0410-93ca-fae66ebed9b2
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Christian Bauer 2005-07-26 01:15:01 +00:00
parent 8614cc883e
commit 883126be26
1 changed files with 24 additions and 8 deletions
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32
reference/en/modules/tutorial.xml
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@ -740,16 +740,32 @@ else if (args[0].equals("list")) {
with the data. You can create more complex queries with HQL, of course.
</para>
<para>
Now, to execute and test all of this, follow these steps:
</para>
<itemizedlist>
<listitem>
<para>
Run <literal>ant run -Daction=store</literal> to store something into the database
and, of course, to generate the database schema before through hbm2ddl.
</para>
</listitem>
<listitem>
<para>
Now disable hbm2ddl by commenting out the property in your <literal>hibernate.cfg.xml</literal>
file. Usually you only leave it turned on in continous unit testing, but another
run of hbm2ddl would <emphasis>drop</emphasis> everything you have stored - the
<literal>create</literal> configuration setting actually translates into "drop all
tables from the schema, then re-create all tables, when the SessionFactory is build".
</para>
</listitem>
</itemizedlist>
<para>
If you now call Ant with <literal>-Daction=list</literal>, you should see the events
you have stored so far. You might be surprised that this doesn't work, at least if you
followed this tutorial step by step - the result will always be empty. The reason for
this is the <literal>hbm2ddl.auto</literal> switch in the Hibernate configuration: Hibernate
will re-create the database on every run. Disable it by removing the option, and you will
see results in your list after you called the <literal>store</literal> action a few
times. Of course the first <literal>store</literal> you do has to have the option turned on,
so you get the initial tables created. Automatic schema generation and export is mostly useful
in unit testing.
you have stored so far. You can of course also call the <literal>store</literal> action a few
times more.
</para>
</sect2>