blocks|key|1164417|text|有趣的是，在Hibernate配置中，我使用的是hibernate.hbm2ddl.auto=update。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1164418|它修改了一个已有的数据库。我手动对表tableName执行DROPping操作，然后重新启动Tomcat，表已经构建好了，但是没有创建索引。|1164419|然而，我做了hibernate.hbm2ddl.auto=create，它在每次webapp的实例化时重新创建数据库，它丢弃了我所有的数据库并重建了回来，-hell是的-我的新索引已经创建了！|1164420|entityMap^0|O|T|0|I|9|0|6|T|0^^$0|@$1|2|3|4|5|6|7|L|8|@$9|M|A|N|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|O|8|@$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|H|3|I|5|6|7|R|8|@$9|S|A|T|B|C]]|D|@]|E|$]]|$1|J|3|-4|5|6|7|U|8|@]|D|@]|E|$]]]|K|$]]

Interestingly, in my Hibernate configuration I was using <code>hibernate.hbm2ddl.auto=update</code>.

This one modifies an existing database. I was manually DROPping the table <code>tableName</code> and restarting Tomcat and the table had been constructed but index was not being created.

However, I made <code>hibernate.hbm2ddl.auto=create</code> which re-creates database upon each instantiation of webapp, it dropped all my database and rebuilt back and -hell yeah- my new index has been created!

blocks|key|950388|text|在Hibernate中故意禁止在模式更新时创建索引，因为它似乎与模式导出中使用的命名不一致。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|950389|这是您可以在org.hibernate.cfg.Configuration类中找到的注释代码。|offset|length|style|CODE|950390|//broken,+'cos+we+don't+generate+these+with+names+in+SchemaExport
subIter+=+table.getIndexIterator();
while+(+subIter.hasNext()+)+{
++++Index+index+=+(Index)+subIter.next();
++++if+(+!index.isForeignKey()+%7C%7C+!dialect.hasImplicitIndexForForeignKey()+)+{
++++++++if+(+tableInfo==null+%7C%7C+tableInfo.getIndexMetadata(+index.getFilterName()+)+==+null+)+{
++++++++++++script.add(+index.sqlCreateString(dialect,+mapping)+);
++++++++}
++++}
}
//broken,+'cos+we+don't+generate+these+with+names+in+SchemaExport
subIter+=+table.getUniqueKeyIterator();
while+(+subIter.hasNext()+)+{
++++UniqueKey+uk+=+(UniqueKey)+subIter.next();
++++if+(+tableInfo==null+%7C%7C+tableInfo.getIndexMetadata(+uk.getFilterName()+)+==+null+)+{
++++++++script.add(+uk.sqlCreateString(dialect,+mapping)+);
++++}
}|code-block|syntax|javascript|950391|通常我会删除该注释，重新编译Hibernate.jar，并在模式更新时创建索引，至少在使用Oracle+DB时不会出现任何问题。|950392|在最近的Hibernate版本中，第一部分(表索引)的注释在官方版本中也被删除了，而对第二部分(实现唯一键的索引)的注释仍然存在。请参阅http://opensource.atlassian.com/projects/hibernate/browse/HHH-1012上的讨论|950393|entityMap|0|LINK|mutability|MUTABLE|url|http://opensource.atlassian.com/projects/hibernate/browse/HHH-1012^0|0|6|V|0|0|0|1W|1U|0|0^^$0|@$1|2|3|4|5|6|7|Y|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|Z|8|@$D|10|E|11|F|G]]|9|@]|A|$]]|$1|H|3|I|5|J|7|12|8|@]|9|@]|A|$K|L]]|$1|M|3|N|5|6|7|13|8|@]|9|@]|A|$]]|$1|O|3|P|5|6|7|14|8|@]|9|@$D|15|E|16|1|17]]|A|$]]|$1|Q|3|-4|5|6|7|18|8|@]|9|@]|A|$]]]|R|$S|$5|T|U|V|A|$W|X]]]]

Index creation on schema update was intentionally disabled in Hibernate because it seemed inconsistent with the naming used in the schema export.

This is the commented code that you can find in class <code>org.hibernate.cfg.Configuration</code>. 

<pre><code>//broken, 'cos we don't generate these with names in SchemaExport
subIter = table.getIndexIterator();
while ( subIter.hasNext() ) {
 Index index = (Index) subIter.next();
 if ( !index.isForeignKey() || !dialect.hasImplicitIndexForForeignKey() ) {
 if ( tableInfo==null || tableInfo.getIndexMetadata( index.getFilterName() ) == null ) {
 script.add( index.sqlCreateString(dialect, mapping) );
 }
 }
}
//broken, 'cos we don't generate these with names in SchemaExport
subIter = table.getUniqueKeyIterator();
while ( subIter.hasNext() ) {
 UniqueKey uk = (UniqueKey) subIter.next();
 if ( tableInfo==null || tableInfo.getIndexMetadata( uk.getFilterName() ) == null ) {
 script.add( uk.sqlCreateString(dialect, mapping) );
 }
}
</code></pre>

Usually I remove that comment, recompile Hibernate.jar and have indexes created on schema update without any problem, at least with Oracle DB.

In recent versions of Hibernate the comment on the first part (table indexes) has been removed in the official version as well, while it's still commented the second one (indexes that implement unique keys).
See the discussion at <a href="http://opensource.atlassian.com/projects/hibernate/browse/HHH-1012">http://opensource.atlassian.com/projects/hibernate/browse/HHH-1012</a>

blocks|key|1164498|text|在Hibernate+3.5.6中，使用<property+name="hibernate.hbm2ddl.auto">update</property>创建索引。因此，现在一个正确的答案是升级。但我把这个答案留给那些像我一样遇到这个问题的人。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1164499|entityMap^0|K|1K|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|K|8|@]|D|@]|E|$]]]|G|$]]

In Hibernate 3.5.6 using <code>&lt;property name="hibernate.hbm2ddl.auto"&gt;update&lt;/property</code>> the indexes are created. So a proper answer now would be to upgrade.
But I'm leaving this answer for those like me that have come across this question.

blocks|key|950481|text|更好的数据库设计意味着模式由不同于数据本身的用户拥有。因此，我设置了hibernate.hbm2ddl.auto=none，这样在Hibernate启动时就不会出现故障。我使用的是SchemaPrinter。它的输出可以通过我最喜欢的SQL工具在需要时重新创建模式。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|950482|import+java.io.IOException;

import+org.hibernate.cfg.AnnotationConfiguration;
import+org.hibernate.cfg.Configuration;
import+org.hibernate.cfg.Environment;
import+org.hibernate.tool.hbm2ddl.SchemaExport;

public+class+SchemaPrinter+{

++++public+static+void+main(String[]+args)+throws+IOException+{

++++++++Configuration+cfg+=+new+AnnotationConfiguration()
++++++++++++.addAnnotatedClass(MyClass1.class)
++++++++++++.addAnnotatedClass(MyClass2.class)
++++++++++++.setProperty(Environment.USER,+"user")
++++++++++++.setProperty(Environment.PASS,+"password")
++++++++++++.setProperty(Environment.URL,+"jdbc:sybase:jndi:file://sql.ini?mydb")
++++++++++++.setProperty(Environment.DIALECT,+"org.hibernate.dialect.SybaseASE15Dialect")
++++++++++++.setProperty(Environment.DRIVER,+"com.sybase.jdbc4.jdbc.SybDriver")
++++++++++++.setProperty(Environment.HBM2DDL_AUTO,+"none")
++++++++SchemaExport+exp+=+new+SchemaExport(cfg);
++++++++exp.setOutputFile("schema.ddl");
++++++++exp.create(true,+false);
++++}

}|code-block|syntax|javascript|950483|entityMap^0|Y|R|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

Better DB design means the schema is owned by a different user than the data itself. Hence I set <code>hibernate.hbm2ddl.auto=none</code> so there are no failures upon Hibernate start. I use a SchemaPrinter instead. The output of which can be run via my favorite SQL tool to recreate the schema when required.

<pre><code>import java.io.IOException;

import org.hibernate.cfg.AnnotationConfiguration;
import org.hibernate.cfg.Configuration;
import org.hibernate.cfg.Environment;
import org.hibernate.tool.hbm2ddl.SchemaExport;

public class SchemaPrinter {

 public static void main(String[] args) throws IOException {

 Configuration cfg = new AnnotationConfiguration()
 .addAnnotatedClass(MyClass1.class)
 .addAnnotatedClass(MyClass2.class)
 .setProperty(Environment.USER, "user")
 .setProperty(Environment.PASS, "password")
 .setProperty(Environment.URL, "jdbc:sybase:jndi:file://sql.ini?mydb")
 .setProperty(Environment.DIALECT, "org.hibernate.dialect.SybaseASE15Dialect")
 .setProperty(Environment.DRIVER, "com.sybase.jdbc4.jdbc.SybDriver")
 .setProperty(Environment.HBM2DDL_AUTO, "none")
 SchemaExport exp = new SchemaExport(cfg);
 exp.setOutputFile("schema.ddl");
 exp.create(true, false);
 }

}
</code></pre>

I have annotation-driven hibernate capabilies on my project.

Now I want to create an index over a column. My current column definition is

<pre><code>@NotNull
@Column(name = "hash")
private String hash;
</code></pre>

and I add <code>@Index</code> annotation here.

<pre><code>@NotNull
@Column(name = "hash")
@Index(name="hashIndex")
private String hash;
</code></pre>

and then DROP TABLE and restart Tomcat server. After the server is instantiated, the table is created but I can't see new index on following query. 

<pre><code>SHOW INDEX FROM tableName
</code></pre>

It is expected to construct table with new index. I am using InnoDB with MySQL.

Creating Indexes on DB with Hibernate @Index Annotation

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我的项目中有注释驱动的hibernate功能。现在我想在列上创建一个索引。我当前的列定义是@NotNull@Column(name = "hash")private String hash;我在这里添加了@Index注释。@NotNull@Column(name = "hash")@Index(name="hashIn...

问使用Hibernate @Index注释在数据库上创建索引
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