collection_mapping.pot

hibernate-distribution-3.3.1.GA-dist.zip源码

#: collection_mapping.xml:274
#, no-c-format
msgid "The contained type is referred to as the <emphasis>collection element type</emphasis>. Collection elements are mapped by <literal>&lt;element&gt;</literal> or <literal>&lt;composite-element&gt;</literal>, or in the case of entity references, with <literal>&lt;one-to-many&gt;</literal> or <literal>&lt;many-to-many&gt;</literal>. The first two map elements with value semantics, the next two are used to map entity associations."
msgstr ""

#. Tag: title
#: collection_mapping.xml:286
#, no-c-format
msgid "Indexed collections"
msgstr ""

#. Tag: para
#: collection_mapping.xml:288
#, no-c-format
msgid "All collection mappings, except those with set and bag semantics, need an <emphasis>index column</emphasis> in the collection table - a column that maps to an array index, or <literal>List</literal> index, or <literal>Map</literal> key. The index of a <literal>Map</literal> may be of any basic type, mapped with <literal>&lt;map-key&gt;</literal>, it may be an entity reference mapped with <literal>&lt;map-key-many-to-many&gt;</literal>, or it may be a composite type, mapped with <literal>&lt;composite-map-key&gt;</literal>. The index of an array or list is always of type <literal>integer</literal> and is mapped using the <literal>&lt;list-index&gt;</literal> element. The mapped column contains sequential integers (numbered from zero, by default)."
msgstr ""

#. Tag: sect2
#: collection_mapping.xml:299
#, no-c-format
msgid ""
      "<programlistingco> <areaspec> <area id=\"index1\" coords=\"2 45\"/> <area id=\"index2\" coords=\"3 45\"/> </areaspec> <programlisting><![CDATA[<list-index \n"
      "        column=\"column_name\"\n"
      "        base=\"0|1|...\"/>]]></programlisting> <calloutlist> <callout arearefs=\"index1\"> <para> <literal>column_name</literal> (required): The name of the column holding the collection index values. </para> </callout> <callout arearefs=\"index1\"> <para> <literal>base</literal> (optional, defaults to <literal>0</literal>): The value of the index column that corresponds to the first element of the list or array. </para> </callout> </calloutlist> </programlistingco> <programlistingco> <areaspec> <area id=\"mapkey1\" coords=\"2 45\"/> <area id=\"mapkey2\" coords=\"3 45\"/> <area id=\"mapkey3\" coords=\"4 45\"/> </areaspec> <programlisting><![CDATA[<map-key \n"
      "        column=\"column_name\"\n"
      "        formula=\"any SQL expression\"\n"
      "        type=\"type_name\"\n"
      "        node=\"@attribute-name\"\n"
      "        length=\"N\"/>]]></programlisting> <calloutlist> <callout arearefs=\"mapkey1\"> <para> <literal>column</literal> (optional): The name of the column holding the collection index values. </para> </callout> <callout arearefs=\"mapkey2\"> <para> <literal>formula</literal> (optional): A SQL formula used to evaluate the key of the map. </para> </callout> <callout arearefs=\"mapkey3\"> <para> <literal>type</literal> (reguired): The type of the map keys. </para> </callout> </calloutlist> </programlistingco> <programlistingco> <areaspec> <area id=\"indexmanytomany1\" coords=\"2 45\"/> <area id=\"indexmanytomany2\" coords=\"3 45\"/> <area id=\"indexmanytomany3\" coords=\"3 45\"/> </areaspec> <programlisting><![CDATA[<map-key-many-to-many\n"
      "        column=\"column_name\"\n"
      "        formula=\"any SQL expression\"\n"
      "        class=\"ClassName\"\n"
      "/>]]></programlisting> <calloutlist> <callout arearefs=\"indexmanytomany1\"> <para> <literal>column</literal> (optional): The name of the foreign key column for the collection index values. </para> </callout> <callout arearefs=\"indexmanytomany2\"> <para> <literal>formula</literal> (optional): A SQL formula used to evaluate the foreign key of the map key. </para> </callout> <callout arearefs=\"indexmanytomany3\"> <para> <literal>class</literal> (required): The entity class used as the map key. </para> </callout> </calloutlist> </programlistingco>"
msgstr ""

#. Tag: para
#: collection_mapping.xml:380
#, no-c-format
msgid "If your table doesn't have an index column, and you still wish to use <literal>List</literal> as the property type, you should map the property as a Hibernate <emphasis>&lt;bag&gt;</emphasis>. A bag does not retain its order when it is retrieved from the database, but it may be optionally sorted or ordered."
msgstr ""

#. Tag: title
#: collection_mapping.xml:390
#, no-c-format
msgid "Collections of values and many-to-many associations"
msgstr ""

#. Tag: para
#: collection_mapping.xml:392
#, no-c-format
msgid "Any collection of values or many-to-many association requires a dedicated <emphasis>collection table</emphasis> with a foreign key column or columns, <emphasis>collection element column</emphasis> or columns and possibly an index column or columns."
msgstr ""

#. Tag: para
#: collection_mapping.xml:399
#, no-c-format
msgid "For a collection of values, we use the <literal>&lt;element&gt;</literal> tag."
msgstr ""

#. Tag: sect2
#: collection_mapping.xml:401
#, no-c-format
msgid ""
      "<programlistingco> <areaspec> <area id=\"element1b\" coords=\"2 50\"/> <area id=\"element2b\" coords=\"3 50\"/> <area id=\"element3b\" coords=\"4 50\"/> </areaspec> <programlisting><![CDATA[<element\n"
      "        column=\"column_name\"\n"
      "        formula=\"any SQL expression\"\n"
      "        type=\"typename\"\n"
      "        length=\"L\"\n"
      "        precision=\"P\"\n"
      "        scale=\"S\"\n"
      "        not-null=\"true|false\"\n"
      "        unique=\"true|false\"\n"
      "        node=\"element-name\"\n"
      "/>]]></programlisting> <calloutlist> <callout arearefs=\"element1b\"> <para> <literal>column</literal> (optional): The name of the column holding the collection element values. </para> </callout> <callout arearefs=\"element2b\"> <para> <literal>formula</literal> (optional): An SQL formula used to evaluate the element. </para> </callout> <callout arearefs=\"element3b\"> <para> <literal>type</literal> (required): The type of the collection element. </para> </callout> </calloutlist> </programlistingco> <para> A <emphasis>many-to-many association</emphasis> is specified using the <literal>&lt;many-to-many&gt;</literal> element. </para> <programlistingco> <areaspec> <area id=\"manytomany1\" coords=\"2 60\"/> <area id=\"manytomany2\" coords=\"3 60\"/> <area id=\"manytomany3\" coords=\"4 60\"/> <area id=\"manytomany4\" coords=\"5 60\"/> <area id=\"manytomany5\" coords=\"6 60\"/> <area id=\"manytomany6\" coords=\"7 60\"/> <area id=\"manytomany7\" coords=\"8 60\"/> <area id=\"manytomany8\" coords=\"9 60\"/> </areaspec> <programlisting><![CDATA[<many-to-many\n"
      "        column=\"column_name\"\n"
      "        formula=\"any SQL expression\"\n"
      "        class=\"ClassName\"\n"
      "        fetch=\"select|join\"\n"
      "        unique=\"true|false\"\n"
      "        not-found=\"ignore|exception\"\n"
      "        entity-name=\"EntityName\"\n"
      "        property-ref=\"propertyNameFromAssociatedClass\"\n"
      "        node=\"element-name\"\n"
      "        embed-xml=\"true|false\"\n"
      "    />]]></programlisting> <calloutlist> <callout arearefs=\"manytomany1\"> <para> <literal>column</literal> (optional): The name of the element foreign key column. </para> </callout> <callout arearefs=\"manytomany2\"> <para> <literal>formula</literal> (optional): An SQL formula used to evaluate the element foreign key value. </para> </callout> <callout arearefs=\"manytomany3\"> <para> <literal>class</literal> (required): The name of the associated class. </para> </callout> <callout arearefs=\"manytomany4\"> <para> <literal>fetch</literal> (optional - defaults to <literal>join</literal>): enables outer-join or sequential select fetching for this association. This is a special case; for full eager fetching (in a single <literal>SELECT</literal>) of an entity and its many-to-many relationships to other entities, you would enable <literal>join</literal> fetching not only of the collection itself, but also with this attribute on the <literal>&lt;many-to-many&gt;</literal> nested element. </para> </callout> <callout arearefs=\"manytomany5\"> <para> <literal>unique</literal> (optional): Enable the DDL generation of a unique constraint for the foreign-key column. This makes the association multiplicity effectively one to many. </para> </callout> <callout arearefs=\"manytomany6\"> <para> <literal>not-found</literal> (optional - defaults to <literal>exception</literal>): Specifies how foreign keys that reference missing rows will be handled: <literal>ignore</literal> will treat a missing row as a null association. </para> </callout> <callout arearefs=\"manytomany7\"> <para> <literal>entity-name</literal> (optional): The entity name of the associated class, as an alternative to <literal>class</literal>. </para> </callout> <callout arearefs=\"manytomany8\"> <para> <literal>property-ref</literal>: (optional) The name of a property of the associated class that is joined to this foreign key. If not specified, the primary key of the associated class is used. </para> </callout> </calloutlist> </programlistingco>"
msgstr ""

#. Tag: para
#: collection_mapping.xml:506
#, no-c-format
msgid "Some examples, first, a set of strings:"
msgstr ""

#. Tag: programlisting
#: collection_mapping.xml:510
#, no-c-format
msgid ""
      "<![CDATA[<set name=\"names\" table=\"person_names\">\n"
      "    <key column=\"person_id\"/>\n"
      "    <element column=\"person_name\" type=\"string\"/>\n"
      "</set>]]>"
msgstr ""

#. Tag: para
#: collection_mapping.xml:512
#, no-c-format
msgid "A bag containing integers (with an iteration order determined by the <literal>order-by</literal> attribute):"
msgstr ""

#. Tag: programlisting
#: collection_mapping.xml:517
#, no-c-format
msgid ""
      "<![CDATA[<bag name=\"sizes\" \n"
      "        table=\"item_sizes\" \n"
      "        order-by=\"size asc\">\n"
      "    <key column=\"item_id\"/>\n"
      "    <element column=\"size\" type=\"integer\"/>\n"
      "</bag>]]>"
msgstr ""

#. Tag: para
#: collection_mapping.xml:519
#, no-c-format
msgid "An array of entities - in this case, a many to many association:"
msgstr ""

#. Tag: programlisting
#: collection_mapping.xml:523
#, no-c-format
msgid ""
      "<![CDATA[<array name=\"addresses\" \n"
      "        table=\"PersonAddress\" \n"
      "        cascade=\"persist\">\n"
      "    <key column=\"personId\"/>\n"
      "    <list-index column=\"sortOrder\"/>\n"
      "    <many-to-many column=\"addressId\" class=\"Address\"/>\n"
      "</array>]]>"
msgstr ""

#. Tag: para
#: collection_mapping.xml:525
#, no-c-format
msgid "A map from string indices to dates:"
msgstr ""

#. Tag: programlisting
#: collection_mapping.xml:529
#, no-c-format
msgid ""
      "<![CDATA[<map name=\"holidays\" \n"
      "        table=\"holidays\" \n"
      "        schema=\"dbo\" \n"
      "        order-by=\"hol_name asc\">\n"
      "    <key column=\"id\"/>\n"
      "    <map-key column=\"hol_name\" type=\"string\"/>\n"
      "    <element column=\"hol_date\" type=\"date\"/>\n"
      "</map>]]>"
msgstr ""

#. Tag: para
#: collection_mapping.xml:531
#, no-c-format
msgid "A list of components (discussed in the next chapter):"
msgstr ""

#. Tag: programlisting
#: collection_mapping.xml:535
#, no-c-format
msgid ""
      "<![CDATA[<list name=\"carComponents\" \n"
      "        table=\"CarComponents\">\n"
      "    <key column=\"carId\"/>\n"
      "    <list-index column=\"sortOrder\"/>\n"
      "    <composite-element class=\"CarComponent\">\n"
      "        <property name=\"price\"/>\n"
      "        <property name=\"type\"/>\n"
      "        <property name=\"serialNumber\" column=\"serialNum\"/>\n"
      "    </composite-element>\n"
      "</list>]]>"
msgstr ""

#. Tag: title
#: collection_mapping.xml:540
#, no-c-format
msgid "One-to-many associations"
msgstr ""

#. Tag: para
#: collection_mapping.xml:542
#, no-c-format
msgid "A <emphasis>one to many association</emphasis> links the tables of two classes via a foreign key, with no intervening collection table. This mapping loses certain semantics of normal Java collections:"
msgstr ""

#. Tag: para
#: collection_mapping.xml:550
#, no-c-format
msgid "An instance of the contained entity class may not belong to more than one instance of the collection"
msgstr ""

#. Tag: para
#: collection_mapping.xml:556
#, no-c-format
msgid "An instance of the contained entity class may not appear at more than one value of the collection index"
msgstr ""

#. Tag: para
#: collection_mapping.xml:563
#, no-c-format
msgid "An association from <literal>Product</literal> to <literal>Part</literal> requires existence of a foreign key column and possibly an index column to the <literal>Part</literal> table. A <literal>&lt;one-to-many&gt;</literal> tag indicates that this is a one to many association."
msgstr ""

#. Tag: programlisting
#: collection_mapping.xml:576
#, no-c-format
msgid ""
      "<![CDATA[<one-to-many \n"
      "        class=\"ClassName\"\n"
      "        not-found=\"ignore|exception\"\n"
      "        entity-name=\"EntityName\"\n"
      "        node=\"element-name\"\n"
      "        embed-xml=\"true|false\"\n"
      "    />]]>"
msgstr ""

#. Tag: para
#: collection_mapping.xml:579
#, no-c-format
msgid "<literal>class</literal> (required): The name of the associated class."
msgstr ""

#. Tag: para
#: collection_mapping.xml:584
#, no-c-format
msgid "<literal>not-found</literal> (optional - defaults to <literal>exception</literal>): Specifies how cached identifiers that reference missing rows will be handled: <literal>ignore</literal> will treat a missing row as a null association."
msgstr ""

#. Tag: para
#: collection_mapping.xml:591
#, no-c-format
msgid "<literal>entity-name</literal> (optional): The entity name of the associated class, as an alternative to <literal>class</literal>."
msgstr ""

#. Tag: para
#: collection_mapping.xml:599
#, no-c-format
msgid "Notice that the <literal>&lt;one-to-many&gt;</literal> element does not need to declare any columns. Nor is it necessary to specify the <literal>table</literal> name anywhere."
msgstr ""

#. Tag: para
#: collection_mapping.xml:605
#, no-c-format
msgid "<emphasis>Very important note:</emphasis> If the foreign key column of a <literal>&lt;one-to-many&gt;</literal> association is declared <literal>NOT NULL</literal>, you must declare the <literal>&lt;key&gt;</literal> mapping <literal>not-null=\"true\"</literal> or <emphasis>use a bidirectional association</emphasis> with the collection mapping marked <literal>inverse=\"true\"</literal>. See the discussion of bidirectional associations later in this chapter."
msgstr ""

#. Tag: para
#: collection_mapping.xml:614
#, no-c-format
msgid "This example shows a map of <literal>Part</literal> entities by name (where <literal>partName</literal> is a persistent property of <literal>Part</literal>). Notice the use of a formula-based index."
msgstr ""

#. Tag: programlisting
#: collection_mapping.xml:620
#, no-c-format
msgid ""
      "<![CDATA[<map name=\"parts\"\n"
      "        cascade=\"all\">\n"
      "    <key column=\"productId\" not-null=\"true\"/>\n"
      "    <map-key formula=\"partName\"/>\n"
      "    <one-to-many class=\"Part\"/>\n"
      "</map>]]>"
msgstr ""

#. Tag: title
#: collection_mapping.xml:626
#, no-c-format
msgid "Advanced collection mappings"
msgstr ""

#. Tag: title
#: collection_mapping.xml:629
#, no-c-format
msgid "Sorted collections"
msgstr ""

#. Tag: para
#: collection_mapping.xml:631
#, no-c-format
msgid "Hibernate supports collections implementing <literal>java.util.SortedMap</literal> and <literal>java.util.SortedSet</literal>. You must specify a comparator in the mapping file:"
msgstr ""

#. Tag: programlisting
#: collection_mapping.xml:636
#, no-c-format
msgid ""
      "<![CDATA[<set name=\"aliases\" \n"
      "            table=\"person_aliases\" \n"
      "            sort=\"natural\">\n"
      "    <key column=\"person\"/>\n"