Hibernate Exception: While migrating from mysql to oracle 11g db - mysql

Question

I am trying to change my application database from mysql to oracle 11g. I am using hibernate in this application but hibernate is throwing:
org.hibernate.exception.SQLGrammarException: could not execute query
at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:90)
at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66)
at org.hibernate.loader.Loader.doList(Loader.java:2231)
at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2125)
at org.hibernate.loader.Loader.list(Loader.java:2120)
at org.hibernate.loader.custom.CustomLoader.list(CustomLoader.java:312)
at org.hibernate.impl.SessionImpl.listCustomQuery(SessionImpl.java:1722)
at org.hibernate.impl.AbstractSessionImpl.list(AbstractSessionImpl.java:165)
at org.hibernate.impl.SQLQueryImpl.list(SQLQueryImpl.java:175)
Below is my hibernate.cfg.xml file:
*<property name="hibernate.connection.driver_class">oracle.jdbc.driver.OracleDriver</property>
<property name="hibernate.dialect">org.hibernate.dialect.Oracle10gDialect</property>
<!-- <property name="hibernate.default_schema">wind</property> -->
<property name="show_sql">true</property>
<property name="hibernate.hbm2ddl.auto">validate</property>
<property name="hibernate.cache.use_second_level_cache">false</property>
<property name="hibernate.cache.use_query_cache">false</property>
<!-- <property name="connection.autoReconnect">true</property> -->
<!-- <property name="hibernate.c3p0.min_size">5</property>
<property name="hibernate.c3p0.max_size">100</property>-->
<property name="hibernate.c3p0.timeout">25200</property>
<property name="hibernate.c3p0.max_statements">50</property>
<property name="hibernate.c3p0.idle_test_period">3000</property>*
I am using one config file for database url and id password.
DATABASE_URL=jdbc:oracle:thin:#localhost:1521/wind
DATABASE_USERNAME=appuser
DATABASE_PASSWORD=appuser
DATABASE_CONN_POOL_MIN=5
DATABASE_CONN_POOL_MAX=50
Mapping file:
<hibernate-mapping>
<class name="com.nsn.abc.entity.UserInfo" table="user_info" >
<id name="id" type="java.lang.Integer">
<column name="id" />
<generator class="assigned" />
</id>
<property name="username" type="string">
<column name="username" length="30" not-null="true" unique="true" />
</property>
<property name="firstName" type="string">
<column name="first_name" length="30" not-null="true" />
</property>
<property name="lastname" type="string">
<column name="lastname" length="30" />
</property>
<property name="email" type="string">
<column name="email" length="50" />
</property>
<property name="password" type="string">
<column name="password" length="30" not-null="true" />
</property>
<property name="phoneNumber" type="string">
<column name="phone_number" length="30" />
</property>
<property name="rights" type="string">
<column name="rights" length="30" not-null="true" />
</property>
<property name="counter" type="int">
<column name="counter" not-null="true" />
</property>
<property name="role" type="string">
<column name="role" length="20" />
</property>
<property name="activeFlag" type="boolean">
<column name="active_flag" not-null="true" />
</property>
<property name="info" type="string">
<column name="info" length="45" />
</property>
<set name="massProvisioningHistories" table="mass_provisioning_history" inverse="true" lazy="true" fetch="select">
<key>
<column name="user_ref" not-null="true" />
</key>
<one-to-many class="com.nsn.abc.entity.MassProvisioningHistory" />
</set>
</class>
</hibernate-mapping>
I have checked all the configuration and other details but still no progress.
Its throwing SQL Error: 923, SQLState: 42000. with ORA-00923: FROM keyword not found where expected
In the logs its genrating below query:
Hibernate: select userinfo0_.id as id25_, userinfo0_.username as username25_, userinfo0_.first_name as first3_25_, userinfo0_.lastname as lastname25_, userinfo0_.email as email25_, userinfo0_.password as password25_, userinfo0_.phone_number as phone7_25_, userinfo0_.rights as rights25_, userinfo0_.counter as counter25_, userinfo0_.role as role25_, userinfo0_.active_flag as active11_25_, userinfo0_.info as info25_ from user_info userinfo0_ where userinfo0_.username=?
Please suggest.
regards,
skr

Answer 1

In the application, we were using the SELECT 1 for checking the hibernate connection.
MySql supports "SELECT 1" but in oracle we need to mention "SELECT 1 from dual".
Now its working fine.
thanks for help.