问题
I'm trying to set up a small working sample of Hibernate that I found here However when I run the code I get the follwing error
Exception in thread "main" org.hibernate.exception.SQLGrammarException: could not insert: [com.sample.Person]
at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:92)
at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66)
at org.hibernate.id.insert.AbstractReturningDelegate.performInsert(AbstractReturningDelegate.java:64)
at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2345)
at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2852)
at org.hibernate.action.EntityIdentityInsertAction.execute(EntityIdentityInsertAction.java:71)
at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:273)
at org.hibernate.event.def.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:320)
at org.hibernate.event.def.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:203)
at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:129)
at .....
Caused by: org.postgresql.util.PSQLException: ERROR: relation "person" does not exist
Position: 13
at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2102)
at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1835)
at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:257)
at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:500)
at org.postgresql.jdbc2.AbstractJdbc2Statement.executeWithFlags(AbstractJdbc2Statement.java:388)
at org.postgresql.jdbc2.AbstractJdbc2Statement.executeUpdate(AbstractJdbc2Statement.java:334)
at org.hibernate.id.IdentityGenerator$GetGeneratedKeysDelegate.executeAndExtract(IdentityGenerator.java:94)
at org.hibernate.id.insert.AbstractReturningDelegate.performInsert(AbstractReturningDelegate.java:57)
... 23 more
But I already have a table by the name person in the database and here's my modified hibernate.cfg.xml
<!-- hibernate dialect -->
<property name="hibernate.dialect">org.hibernate.dialect.MySQLInnoDBDialect</property>
<property name="hibernate.connection.driver_class">org.postgresql.Driver</property>
<property name="hibernate.connection.url">jdbc:postgresql://localhost/testDB</property>
<property name="hibernate.connection.username">postgres</property>
<property name="hibernate.connection.password"></property>
<property name="hibernate.show.sql" ></property>
<property name="transaction.factory_class">org.hibernate.transaction.JDBCTransactionFactory</property>
<!-- Automatic schema creation (begin) === -->
<property name="hibernate.hbm2ddl.auto">create</property>
<!-- Simple memory-only cache -->
<property name="hibernate.cache.provider_class">org.hibernate.cache.HashtableCacheProvider</property>
<!-- Enable Hibernate's automatic session context management -->
<property name="current_session_context_class">thread</property>
<!-- ############################################ -->
<!-- # mapping files with external dependencies # -->
<!-- ############################################ -->
<mapping resource="com/sample/Person.hbm.xml" />
</session-factory>
It would be great if anyone could point out what Im doing wrong, as this is my first attempt at Hibernate. Thanks!
EDIT: Person.hbm.xml
<class name="com.sample.Person" table="person">
<id name="id" column="ID">
<generator class="native" />
</id>
<property name="name">
<column name="NAME" length="16" not-null="true" />
</property>
<property name="surname">
<column name="SURNAME" length="16" not-null="true" />
</property>
<property name="address">
<column name="ADDRESS" length="16" not-null="true" />
</property>
</class>
EDIT-II: Content of the log file (Postgresql.log)
2012-02-13 09:23:25 IST LOG: database system was shut down at 2012-02-10 18:14:57 IST
2012-02-13 09:23:25 IST FATAL: the database system is starting up
2012-02-13 09:23:33 IST LOG: database system is ready to accept connections
2012-02-13 09:23:38 IST LOG: autovacuum launcher started
2012-02-13 09:46:01 IST ERROR: syntax error at or near "auto_increment" at character 41
2012-02-13 09:46:01 IST STATEMENT: create table person (ID bigint not null auto_increment, NAME varchar(16) not null, SURNAME varchar(16) not null, ADDRESS varchar(16) not null, primary key (ID)) type=InnoDB
2012-02-13 09:46:01 IST ERROR: relation "person" does not exist at character 13
2012-02-13 09:46:01 IST STATEMENT: insert into person (NAME, SURNAME, ADDRESS) values ($1, $2, $3) RETURNING *
2012-02-13 09:46:01 IST LOG: could not receive data from client: No connection could be made because the target machine actively refused it.
2012-02-13 09:46:01 IST LOG: unexpected EOF on client connection
2012-02-13 09:48:15 IST ERROR: syntax error at or near "auto_increment" at character 41
2012-02-13 09:48:15 IST STATEMENT: create table person (ID bigint not null auto_increment, NAME varchar(16) not null, SURNAME varchar(16) not null, ADDRESS varchar(16) not null, primary key (ID)) type=InnoDB
2012-02-13 09:48:15 IST ERROR: relation "person" does not exist at character 13
2012-02-13 09:48:15 IST STATEMENT: insert into person (NAME, SURNAME, ADDRESS) values ($1, $2, $3) RETURNING *
2012-02-13 09:48:15 IST LOG: could not receive data from client: No connection could be made because the target machine actively refused it.
2012-02-13 09:48:15 IST LOG: unexpected EOF on client connection
UPDATE: I just noticed something weird, I create the relation in the DB and then run this piece of code, only to see that the table gets deleted as in it just dissapears when I run this code; any idea why this happens?
回答1:
I solved the error by modifying the following property in hibernate.cfg.xml
<property name="hibernate.hbm2ddl.auto">validate</property>
Earlier, the table was getting deleted each time I ran the program and now it doesnt, as hibernate only validates the schema and does not affect changes to it.
回答2:
According to the exception, Hibernate wants to write to the table "person", yet in your hbm.xml you define that there is a table "Person", are you sure the correct table exists in your database-schema?
回答3:
Note:
Its not necessary to specify table name in Person.hbm.xml (........) when you are creating table with same as class name. Also applicable to fields.
While creating "person" table in your respective database,make sure that whatever FILEDS names you specified in Person.hbm.xml must match with table COLUMNS names ELSE you wil get above error.
回答4:
The problem in my case was that the database name was incorrect.
I solved the problem by referring the correct database name in the field as below
<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/myDatabase</property>
回答5:
It seems you are connecting to the wrong database. R u sure "jdbc:postgresql://localhost/testDB" will connect you to the actual datasource ?
Generally they are of the form "jdbc://hostname/databasename". Look into Postgresql log file.
回答6:
I solved the error by modifying the following property in hibernate.cfg.xml
<property name="hibernate.hbm2ddl.auto">validate</property>
Earlier, the table was getting deleted each time I ran the program and now it doesnt, as hibernate only validates the schema and does not affect changes to it.
As far as I know you can also change from validate to update e.g.:
<property name="hibernate.hbm2ddl.auto">update</property>
回答7:
You may try to put the right database name in connection url in the configuration file. As I had the same error while run the POJO class file and it has been solved by this.
回答8:
I sovled this errors by modifying the Database charset.Old Database charset is cp1252 and i conver to utf-8
回答9:
What do we mean by org.hibernate.exception.SQLGrammarException?
Implementation of JDBCException indicating that the SQL sent to the database server was invalid (syntax error, invalid object references, etc).
and in my words there is a kind of Grammar mistake inside of your hibernate.cfg.xml configuration file,
it happens when you write wrong schema defination property name inside, like below example:
<property name="hibernate.connection.hbm2ddl.auto">create</property>
which supposed to be like:
<property name="hibernate.hbm2ddl.auto">create</property>
来源：https://stackoverflow.com/questions/9227328/org-hibernate-exception-sqlgrammarexception-could-not-insert-com-sample-person