basic_mapping.pot

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

#, no-c-format
msgid "There is an alternative <literal>&lt;composite-id&gt;</literal> declaration to allow access to legacy data with composite keys. We strongly discourage its use for anything else."
msgstr ""

#. Tag: title
#: basic_mapping.xml:556
#, no-c-format
msgid "Generator"
msgstr ""

#. Tag: para
#: basic_mapping.xml:558
#, no-c-format
msgid "The optional <literal>&lt;generator&gt;</literal> child element names a Java class used to generate unique identifiers for instances of the persistent class. If any parameters are required to configure or initialize the generator instance, they are passed using the <literal>&lt;param&gt;</literal> element."
msgstr ""

#. Tag: programlisting
#: basic_mapping.xml:565
#, no-c-format
msgid ""
      "<![CDATA[<id name=\"id\" type=\"long\" column=\"cat_id\">\n"
      "        <generator class=\"org.hibernate.id.TableHiLoGenerator\">\n"
      "                <param name=\"table\">uid_table</param>\n"
      "                <param name=\"column\">next_hi_value_column</param>\n"
      "        </generator>\n"
      "</id>]]>"
msgstr ""

#. Tag: para
#: basic_mapping.xml:567
#, no-c-format
msgid "All generators implement the interface <literal>org.hibernate.id.IdentifierGenerator</literal>. This is a very simple interface; some applications may choose to provide their own specialized implementations. However, Hibernate provides a range of built-in implementations. There are shortcut names for the built-in generators:"
msgstr ""

#. Tag: literal
#: basic_mapping.xml:575
#, no-c-format
msgid "increment"
msgstr ""

#. Tag: para
#: basic_mapping.xml:577
#, no-c-format
msgid "generates identifiers of type <literal>long</literal>, <literal>short</literal> or <literal>int</literal> that are unique only when no other process is inserting data into the same table. <emphasis>Do not use in a cluster.</emphasis>"
msgstr ""

#. Tag: literal
#: basic_mapping.xml:586
#, no-c-format
msgid "identity"
msgstr ""

#. Tag: para
#: basic_mapping.xml:588
#, no-c-format
msgid "supports identity columns in DB2, MySQL, MS SQL Server, Sybase and HypersonicSQL. The returned identifier is of type <literal>long</literal>, <literal>short</literal> or <literal>int</literal>."
msgstr ""

#. Tag: literal
#: basic_mapping.xml:596
#, no-c-format
msgid "sequence"
msgstr ""

#. Tag: para
#: basic_mapping.xml:598
#, no-c-format
msgid "uses a sequence in DB2, PostgreSQL, Oracle, SAP DB, McKoi or a generator in Interbase. The returned identifier is of type <literal>long</literal>, <literal>short</literal> or <literal>int</literal>"
msgstr ""

#. Tag: literal
#: basic_mapping.xml:606
#, no-c-format
msgid "hilo"
msgstr ""

#. Tag: para
#: basic_mapping.xml:608
#, no-c-format
msgid "uses a hi/lo algorithm to efficiently generate identifiers of type <literal>long</literal>, <literal>short</literal> or <literal>int</literal>, given a table and column (by default <literal>hibernate_unique_key</literal> and <literal>next_hi</literal> respectively) as a source of hi values. The hi/lo algorithm generates identifiers that are unique only for a particular database."
msgstr ""

#. Tag: literal
#: basic_mapping.xml:618
#, no-c-format
msgid "seqhilo"
msgstr ""

#. Tag: para
#: basic_mapping.xml:620
#, no-c-format
msgid "uses a hi/lo algorithm to efficiently generate identifiers of type <literal>long</literal>, <literal>short</literal> or <literal>int</literal>, given a named database sequence."
msgstr ""

#. Tag: literal
#: basic_mapping.xml:628
#, no-c-format
msgid "uuid"
msgstr ""

#. Tag: para
#: basic_mapping.xml:630
#, no-c-format
msgid "uses a 128-bit UUID algorithm to generate identifiers of type string, unique within a network (the IP address is used). The UUID is encoded as a string of hexadecimal digits of length 32."
msgstr ""

#. Tag: literal
#: basic_mapping.xml:638
#, no-c-format
msgid "guid"
msgstr ""

#. Tag: para
#: basic_mapping.xml:640
#, no-c-format
msgid "uses a database-generated GUID string on MS SQL Server and MySQL."
msgstr ""

#. Tag: literal
#: basic_mapping.xml:646
#, no-c-format
msgid "native"
msgstr ""

#. Tag: para
#: basic_mapping.xml:648
#, no-c-format
msgid "picks <literal>identity</literal>, <literal>sequence</literal> or <literal>hilo</literal> depending upon the capabilities of the underlying database."
msgstr ""

#. Tag: literal
#: basic_mapping.xml:656
#, no-c-format
msgid "assigned"
msgstr ""

#. Tag: para
#: basic_mapping.xml:658
#, no-c-format
msgid "lets the application to assign an identifier to the object before <literal>save()</literal> is called. This is the default strategy if no <literal>&lt;generator&gt;</literal> element is specified."
msgstr ""

#. Tag: literal
#: basic_mapping.xml:666
#, no-c-format
msgid "select"
msgstr ""

#. Tag: para
#: basic_mapping.xml:668
#, no-c-format
msgid "retrieves a primary key assigned by a database trigger by selecting the row by some unique key and retrieving the primary key value."
msgstr ""

#. Tag: literal
#: basic_mapping.xml:675
#, no-c-format
msgid "foreign"
msgstr ""

#. Tag: para
#: basic_mapping.xml:677
#, no-c-format
msgid "uses the identifier of another associated object. Usually used in conjunction with a <literal>&lt;one-to-one&gt;</literal> primary key association."
msgstr ""

#. Tag: literal
#: basic_mapping.xml:684
#, no-c-format
msgid "sequence-identity"
msgstr ""

#. Tag: para
#: basic_mapping.xml:686
#, no-c-format
msgid "a specialized sequence generation strategy which utilizes a database sequence for the actual value generation, but combines this with JDBC3 getGeneratedKeys to actually return the generated identifier value as part of the insert statement execution. This strategy is only known to be supported on Oracle 10g drivers targetted for JDK 1.4. Note comments on these insert statements are disabled due to a bug in the Oracle drivers."
msgstr ""

#. Tag: title
#: basic_mapping.xml:703
#, no-c-format
msgid "Hi/lo algorithm"
msgstr ""

#. Tag: para
#: basic_mapping.xml:704
#, no-c-format
msgid "The <literal>hilo</literal> and <literal>seqhilo</literal> generators provide two alternate implementations of the hi/lo algorithm, a favorite approach to identifier generation. The first implementation requires a \"special\" database table to hold the next available \"hi\" value. The second uses an Oracle-style sequence (where supported)."
msgstr ""

#. Tag: programlisting
#: basic_mapping.xml:711
#, no-c-format
msgid ""
      "<![CDATA[<id name=\"id\" type=\"long\" column=\"cat_id\">\n"
      "        <generator class=\"hilo\">\n"
      "                <param name=\"table\">hi_value</param>\n"
      "                <param name=\"column\">next_value</param>\n"
      "                <param name=\"max_lo\">100</param>\n"
      "        </generator>\n"
      "</id>]]>"
msgstr ""

#. Tag: programlisting
#: basic_mapping.xml:713
#, no-c-format
msgid ""
      "<![CDATA[<id name=\"id\" type=\"long\" column=\"cat_id\">\n"
      "        <generator class=\"seqhilo\">\n"
      "                <param name=\"sequence\">hi_value</param>\n"
      "                <param name=\"max_lo\">100</param>\n"
      "        </generator>\n"
      "</id>]]>"
msgstr ""

#. Tag: para
#: basic_mapping.xml:715
#, no-c-format
msgid "Unfortunately, you can't use <literal>hilo</literal> when supplying your own <literal>Connection</literal> to Hibernate. When Hibernate is using an application server datasource to obtain connections enlisted with JTA, you must properly configure the <literal>hibernate.transaction.manager_lookup_class</literal>."
msgstr ""

#. Tag: title
#: basic_mapping.xml:724
#, no-c-format
msgid "UUID algorithm"
msgstr ""

#. Tag: para
#: basic_mapping.xml:725
#, no-c-format
msgid "The UUID contains: IP address, startup time of the JVM (accurate to a quarter second), system time and a counter value (unique within the JVM). It's not possible to obtain a MAC address or memory address from Java code, so this is the best we can do without using JNI."
msgstr ""

#. Tag: title
#: basic_mapping.xml:734
#, no-c-format
msgid "Identity columns and sequences"
msgstr ""

#. Tag: para
#: basic_mapping.xml:735
#, no-c-format
msgid "For databases which support identity columns (DB2, MySQL, Sybase, MS SQL), you may use <literal>identity</literal> key generation. For databases that support sequences (DB2, Oracle, PostgreSQL, Interbase, McKoi, SAP DB) you may use <literal>sequence</literal> style key generation. Both these strategies require two SQL queries to insert a new object."
msgstr ""

#. Tag: programlisting
#: basic_mapping.xml:743
#, no-c-format
msgid ""
      "<![CDATA[<id name=\"id\" type=\"long\" column=\"person_id\">\n"
      "        <generator class=\"sequence\">\n"
      "                <param name=\"sequence\">person_id_sequence</param>\n"
      "        </generator>\n"
      "</id>]]>"
msgstr ""

#. Tag: programlisting
#: basic_mapping.xml:745
#, no-c-format
msgid ""
      "<![CDATA[<id name=\"id\" type=\"long\" column=\"person_id\" unsaved-value=\"0\">\n"
      "        <generator class=\"identity\"/>\n"
      "</id>]]>"
msgstr ""

#. Tag: para
#: basic_mapping.xml:747
#, no-c-format
msgid "For cross-platform development, the <literal>native</literal> strategy will choose from the <literal>identity</literal>, <literal>sequence</literal> and <literal>hilo</literal> strategies, dependant upon the capabilities of the underlying database."
msgstr ""

#. Tag: title
#: basic_mapping.xml:756
#, no-c-format
msgid "Assigned identifiers"
msgstr ""

#. Tag: para
#: basic_mapping.xml:757
#, no-c-format
msgid "If you want the application to assign identifiers (as opposed to having Hibernate generate them), you may use the <literal>assigned</literal> generator. This special generator will use the identifier value already assigned to the object's identifier property. This generator is used when the primary key is a natural key instead of a surrogate key. This is the default behavior if you do no specify a <literal>&lt;generator&gt;</literal> element."
msgstr ""

#. Tag: para
#: basic_mapping.xml:766
#, no-c-format
msgid "Choosing the <literal>assigned</literal> generator makes Hibernate use <literal>unsaved-value=\"undefined\"</literal>, forcing Hibernate to go to the database to determine if an instance is transient or detached, unless there is a version or timestamp property, or you define <literal>Interceptor.isUnsaved()</literal>."
msgstr ""

#. Tag: title
#: basic_mapping.xml:776
#, no-c-format
msgid "Primary keys assigned by triggers"
msgstr ""

#. Tag: para
#: basic_mapping.xml:777
#, no-c-format
msgid "For legacy schemas only (Hibernate does not generate DDL with triggers)."
msgstr ""

#. Tag: programlisting
#: basic_mapping.xml:781
#, no-c-format
msgid ""
      "<![CDATA[<id name=\"id\" type=\"long\" column=\"person_id\">\n"
      "        <generator class=\"select\">\n"
      "                <param name=\"key\">socialSecurityNumber</param>\n"
      "        </generator>\n"
      "</id>]]>"