HHH-8790 added @Filter deduceAliasInjectionPoints info and examples to

user guide
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Brett Meyer 2014-01-02 17:44:18 -05:00
parent 781536c9d7
commit eb1beb8a99
1 changed files with 30 additions and 7 deletions

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@ -63,15 +63,38 @@ public class Forest { ... }</programlisting>
<title>Using <classname>@FilterJoinTable</classname> for filterting on
the association table</title>
<programlisting language="JAVA" role="JAVA"> @OneToMany
@JoinTable
//filter on the target entity table
@Filter(name="betweenLength", condition=":minLength &lt;= length and :maxLength &gt;= length")
//filter on the association table
@FilterJoinTable(name="security", condition=":userlevel &gt;= requredLevel")
public Set&lt;Forest&gt; getForests() { ... }</programlisting>
<programlisting language="JAVA" role="JAVA">@OneToMany
@JoinTable
//filter on the target entity table
@Filter(name="betweenLength", condition=":minLength &lt;= length and :maxLength &gt;= length")
//filter on the association table
@FilterJoinTable(name="security", condition=":userlevel &gt;= requredLevel")
public Set&lt;Forest&gt; getForests() { ... }</programlisting>
</example>
<para>By default, Hibernate attempts to automatically determine all points within the
<literal>@Filter</literal> SQL condition fragment that an alias should be injected. To control the alias injection,
set <literal>deduceAliasInjectionPoints</literal> to <literal>false</literal> within the
<literal>@Filter</literal>. Injection points are then marked using <literal>@SqlFragmentAlias</literal> annotations or
within the SQL's condition fragment using <literal>{alias}</literal>.</para>
<para>In addition to allowing explicit alias control, <literal>deduceAliasInjectionPoints</literal>
provides an out when Hibernate assumes an ANSI SQL reserved keyword is a column and incorrectly aliases it.</para>
<example>
<title>@Filter annotation, disabling deduceAliasInjectionPoints</title>
<programlisting language="JAVA" role="JAVA">@Entity
@Table(name="T_TREE")
@Filters({
@Filter(name="isTall", condition="{alias}.LENGTH &gt;= 100", deduceAliasInjectionPoints = false),
@Filter(name="isOak", condition="{t}.WOODTYPE like 'oak'", deduceAliasInjectionPoints = false,
aliases={@SqlFragmentAlias(alias="t", table="T_TREE")})
})
public class Tree { ... }
</programlisting>
</example>
<para>Using Hibernate mapping files for defining filters the situtation is
very similar. The filters must first be defined and then attached to the
appropriate mapping elements. To define a filter, use the