association_mapping.pot

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

# SOME DESCRIPTIVE TITLE.
# FIRST AUTHOR <EMAIL@ADDRESS>, YEAR.
#
#, fuzzy
msgid ""
msgstr ""
"Project-Id-Version: PACKAGE VERSION\n"
"Report-Msgid-Bugs-To: http://bugs.kde.org\n"
"POT-Creation-Date: 2008-08-14 15:28+0000\n"
"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
"Language-Team: LANGUAGE <[e-mail]>\n"
"MIME-Version: 1.0\n"
"Content-Type: application/x-xml2pot; charset=UTF-8\n"
"Content-Transfer-Encoding: 8bit\n"

#. Tag: title
#: association_mapping.xml:30
#, no-c-format
msgid "Association Mappings"
msgstr ""

#. Tag: title
#: association_mapping.xml:33
#, no-c-format
msgid "Introduction"
msgstr ""

#. Tag: para
#: association_mapping.xml:35
#, no-c-format
msgid "Association mappings are the often most difficult thing to get right. In this section we'll go through the canonical cases one by one, starting with unidirectional mappings, and then considering the bidirectional cases. We'll use <literal>Person</literal> and <literal>Address</literal> in all the examples."
msgstr ""

#. Tag: para
#: association_mapping.xml:43
#, no-c-format
msgid "We'll classify associations by whether or not they map to an intervening join table, and by multiplicity."
msgstr ""

#. Tag: para
#: association_mapping.xml:48
#, no-c-format
msgid "Nullable foreign keys are not considered good practice in traditional data modelling, so all our examples use not null foreign keys. This is not a requirement of Hibernate, and the mappings will all work if you drop the nullability constraints."
msgstr ""

#. Tag: title
#: association_mapping.xml:58
#, no-c-format
msgid "Unidirectional associations"
msgstr ""

#. Tag: title
#: association_mapping.xml:61 association_mapping.xml:132
#, no-c-format
msgid "many to one"
msgstr ""

#. Tag: para
#: association_mapping.xml:63
#, no-c-format
msgid "A <emphasis>unidirectional many-to-one association</emphasis> is the most common kind of unidirectional association."
msgstr ""

#. Tag: programlisting
#: association_mapping.xml:68
#, no-c-format
msgid ""
      "<![CDATA[<class name=\"Person\">\n"
      "    <id name=\"id\" column=\"personId\">\n"
      "        <generator class=\"native\"/>\n"
      "    </id>\n"
      "    <many-to-one name=\"address\" \n"
      "        column=\"addressId\"\n"
      "        not-null=\"true\"/>\n"
      "</class>\n"
      "\n"
      "<class name=\"Address\">\n"
      "    <id name=\"id\" column=\"addressId\">\n"
      "        <generator class=\"native\"/>\n"
      "    </id>\n"
      "</class>]]>"
msgstr ""

#. Tag: programlisting
#: association_mapping.xml:69 association_mapping.xml:185
#, no-c-format
msgid ""
      "<![CDATA[\n"
      "create table Person ( personId bigint not null primary key, addressId bigint not null )\n"
      "create table Address ( addressId bigint not null primary key )\n"
      "        ]]>"
msgstr ""

#. Tag: title
#: association_mapping.xml:74 association_mapping.xml:145 association_mapping.xml:209 association_mapping.xml:249
#, no-c-format
msgid "one to one"
msgstr ""

#. Tag: para
#: association_mapping.xml:76
#, no-c-format
msgid "A <emphasis>unidirectional one-to-one association on a foreign key</emphasis> is almost identical. The only difference is the column unique constraint."
msgstr ""

#. Tag: programlisting
#: association_mapping.xml:81
#, no-c-format
msgid ""
      "<![CDATA[<class name=\"Person\">\n"
      "    <id name=\"id\" column=\"personId\">\n"
      "        <generator class=\"native\"/>\n"
      "    </id>\n"
      "    <many-to-one name=\"address\" \n"
      "        column=\"addressId\" \n"
      "        unique=\"true\"\n"
      "        not-null=\"true\"/>\n"
      "</class>\n"
      "\n"
      "<class name=\"Address\">\n"
      "    <id name=\"id\" column=\"addressId\">\n"
      "        <generator class=\"native\"/>\n"
      "    </id>\n"
      "</class>]]>"
msgstr ""

#. Tag: programlisting
#: association_mapping.xml:82 association_mapping.xml:217
#, no-c-format
msgid ""
      "<![CDATA[\n"
      "create table Person ( personId bigint not null primary key, addressId bigint not null unique )\n"
      "create table Address ( addressId bigint not null primary key )\n"
      "        ]]>"
msgstr ""

#. Tag: para
#: association_mapping.xml:84
#, no-c-format
msgid "A <emphasis>unidirectional one-to-one association on a primary key</emphasis> usually uses a special id generator. (Notice that we've reversed the direction of the association in this example.)"
msgstr ""

#. Tag: programlisting
#: association_mapping.xml:90
#, no-c-format
msgid ""
      "<![CDATA[<class name=\"Person\">\n"
      "    <id name=\"id\" column=\"personId\">\n"
      "        <generator class=\"native\"/>\n"
      "    </id>\n"
      "</class>\n"
      "\n"
      "<class name=\"Address\">\n"
      "    <id name=\"id\" column=\"personId\">\n"
      "        <generator class=\"foreign\">\n"
      "            <param name=\"property\">person</param>\n"
      "        </generator>\n"
      "    </id>\n"
      "    <one-to-one name=\"person\" constrained=\"true\"/>\n"
      "</class>]]>"
msgstr ""

#. Tag: programlisting
#: association_mapping.xml:91 association_mapping.xml:225
#, no-c-format
msgid ""
      "<![CDATA[\n"
      "create table Person ( personId bigint not null primary key )\n"
      "create table Address ( personId bigint not null primary key )\n"
      "        ]]>"
msgstr ""

#. Tag: title
#: association_mapping.xml:96 association_mapping.xml:118
#, no-c-format
msgid "one to many"
msgstr ""

#. Tag: para
#: association_mapping.xml:98
#, no-c-format
msgid "A <emphasis>unidirectional one-to-many association on a foreign key</emphasis> is a very unusual case, and is not really recommended."
msgstr ""

#. Tag: programlisting
#: association_mapping.xml:103
#, no-c-format
msgid ""
      "<![CDATA[<class name=\"Person\">\n"
      "    <id name=\"id\" column=\"personId\">\n"
      "        <generator class=\"native\"/>\n"
      "    </id>\n"
      "    <set name=\"addresses\">\n"
      "        <key column=\"personId\" \n"
      "            not-null=\"true\"/>\n"
      "        <one-to-many class=\"Address\"/>\n"
      "    </set>\n"
      "</class>\n"
      "\n"
      "<class name=\"Address\">\n"
      "    <id name=\"id\" column=\"addressId\">\n"
      "        <generator class=\"native\"/>\n"
      "    </id>\n"
      "</class>]]>"
msgstr ""

#. Tag: programlisting
#: association_mapping.xml:104
#, no-c-format
msgid ""
      "<![CDATA[\n"
      "create table Person ( personId bigint not null primary key )\n"
      "create table Address ( addressId bigint not null primary key, personId bigint not null )\n"
      "        ]]>"
msgstr ""

#. Tag: para
#: association_mapping.xml:106
#, no-c-format
msgid "We think it's better to use a join table for this kind of association."
msgstr ""

#. Tag: title
#: association_mapping.xml:115
#, no-c-format
msgid "Unidirectional associations with join tables"
msgstr ""

#. Tag: para
#: association_mapping.xml:120
#, no-c-format
msgid "A <emphasis>unidirectional one-to-many association on a join table</emphasis> is much preferred. Notice that by specifying <literal>unique=\"true\"</literal>, we have changed the multiplicity from many-to-many to one-to-many."
msgstr ""

#. Tag: programlisting
#: association_mapping.xml:126
#, no-c-format
msgid ""
      "<![CDATA[<class name=\"Person\">\n"
      "    <id name=\"id\" column=\"personId\">\n"
      "        <generator class=\"native\"/>\n"
      "    </id>\n"
      "    <set name=\"addresses\" table=\"PersonAddress\">\n"
      "        <key column=\"personId\"/>\n"
      "        <many-to-many column=\"addressId\"\n"
      "            unique=\"true\"\n"
      "            class=\"Address\"/>\n"
      "    </set>\n"
      "</class>\n"
      "\n"
      "<class name=\"Address\">\n"
      "    <id name=\"id\" column=\"addressId\">\n"
      "        <generator class=\"native\"/>\n"
      "    </id>\n"
      "</class>]]>"
msgstr ""

#. Tag: programlisting
#: association_mapping.xml:127
#, no-c-format
msgid ""
      "<![CDATA[\n"
      "create table Person ( personId bigint not null primary key )\n"
      "create table PersonAddress ( personId not null, addressId bigint not null primary key )\n"
      "create table Address ( addressId bigint not null primary key )\n"
      "        ]]>"
msgstr ""

#. Tag: para
#: association_mapping.xml:134
#, no-c-format
msgid "A <emphasis>unidirectional many-to-one association on a join table</emphasis> is quite common when the association is optional."
msgstr ""

#. Tag: programlisting
#: association_mapping.xml:139
#, no-c-format
msgid ""
      "<![CDATA[<class name=\"Person\">\n"
      "    <id name=\"id\" column=\"personId\">\n"
      "        <generator class=\"native\"/>\n"
      "    </id>\n"
      "    <join table=\"PersonAddress\" \n"
      "        optional=\"true\">\n"
      "        <key column=\"personId\" unique=\"true\"/>\n"
      "        <many-to-one name=\"address\"\n"
      "            column=\"addressId\" \n"
      "            not-null=\"true\"/>\n"
      "    </join>\n"
      "</class>\n"
      "\n"
      "<class name=\"Address\">\n"
      "    <id name=\"id\" column=\"addressId\">\n"
      "        <generator class=\"native\"/>\n"
      "    </id>\n"
      "</class>]]>"
msgstr ""

#. Tag: programlisting
#: association_mapping.xml:140
#, no-c-format
msgid ""
      "<![CDATA[\n"
      "create table Person ( personId bigint not null primary key )\n"
      "create table PersonAddress ( personId bigint not null primary key, addressId bigint not null )\n"
      "create table Address ( addressId bigint not null primary key )\n"
      "        ]]>"
msgstr ""

#. Tag: para
#: association_mapping.xml:147
#, no-c-format
msgid "A <emphasis>unidirectional one-to-one association on a join table</emphasis> is extremely unusual, but possible."
msgstr ""

#. Tag: programlisting
#: association_mapping.xml:152
#, no-c-format
msgid ""
      "<![CDATA[<class name=\"Person\">\n"
      "    <id name=\"id\" column=\"personId\">\n"
      "        <generator class=\"native\"/>\n"
      "    </id>\n"
      "    <join table=\"PersonAddress\" \n"
      "        optional=\"true\">\n"
      "        <key column=\"personId\" \n"
      "            unique=\"true\"/>\n"
      "        <many-to-one name=\"address\"\n"
      "            column=\"addressId\" \n"
      "            not-null=\"true\"\n"
      "            unique=\"true\"/>\n"
      "    </join>\n"
      "</class>\n"
      "\n"
      "<class name=\"Address\">\n"
      "    <id name=\"id\" column=\"addressId\">\n"
      "        <generator class=\"native\"/>\n"
      "    </id>\n"
      "</class>]]>"
msgstr ""

#. Tag: programlisting
#: association_mapping.xml:153 association_mapping.xml:257
#, no-c-format
msgid ""
      "<![CDATA[\n"
      "create table Person ( personId bigint not null primary key )\n"
      "create table PersonAddress ( personId bigint not null primary key, addressId bigint not null unique )\n"
      "create table Address ( addressId bigint not null primary key )\n"
      "        ]]>"
msgstr ""

#. Tag: title
#: association_mapping.xml:158 association_mapping.xml:262
#, no-c-format
msgid "many to many"
msgstr ""

#. Tag: para
#: association_mapping.xml:160
#, no-c-format
msgid "Finally, we have a <emphasis>unidirectional many-to-many association</emphasis>."
msgstr ""

#. Tag: programlisting
#: association_mapping.xml:164
#, no-c-format
msgid ""
      "<![CDATA[<class name=\"Person\">\n"