We will use Bean, Utilty and DAO classes created in last article
for basic hibernate configuration then we will use two features of Hibernate
called named query and named native query for fetching list of employees filtered
by their first name.
Named Query: We map Hibernate Query to some
logical name and use this name to get required results.
Named Native Query: We map raw JDBC query to
some logical name and use this name to get required results.
So we will use same EmployeeDAO and
EmployeeBean for this example. We will use following annotations for
configuring these queries in hibernate
@NamedQueries: List of named queries
@NamedQuery: To map hibernate query to its logical name.
@NamedNativeQueries: List of named native queries
@NamedNativeQuery: To map raw/native JDBC query to its logical
name.
We will start with Named Query and then there
is a minor change that we will make to use named native query. So we will add @NamedQueries tag and in its
argument we will pass list of queries with annotations @NamedQuery.
@NamedQueries({
@NamedQuery(name="get-emp-by-name",query="FROM
EmployeeBean WHERE fName=:fName")
})
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And in DAO class we will add one method that
will accept name and return list of EmployeeBean.
public
List<EmployeeBean> getEmployeeListByName(String name){
Session sess = null;
try{
sess
= HibernateUtil.getSession();
Query
qry = sess.getNamedQuery("get-emp-by-name"); //Get the query
qry.setString("fName", name); //Set the
parameter
System.out.println(qry.getQueryString());
//Check
what query is fetched
return qry.list();
//Return
the list of results
}
catch(HibernateException e){
e.printStackTrace();//Later remove
this by appropriate logger statement or throw custom exception
}
finally{
HibernateUtil.closeSession(sess);
}
return null;
}
|
When this code is executed it will give
following result.
Jan 08, 2014 7:41:14
PM org.hibernate.annotations.common.reflection.java.JavaReflectionManager
<clinit>
INFO: HCANN000001:
Hibernate Commons Annotations {4.0.4.Final}
Jan 08, 2014 7:41:14
PM org.hibernate.Version logVersion
INFO: HHH000412:
Hibernate Core {4.3.0.Final}
Jan 08, 2014 7:41:14
PM org.hibernate.cfg.Environment <clinit>
INFO: HHH000206:
hibernate.properties not found
Jan 08, 2014 7:41:14
PM org.hibernate.cfg.Environment buildBytecodeProvider
INFO: HHH000021:
Bytecode provider name : javassist
Jan 08, 2014 7:41:14
PM org.hibernate.cfg.Configuration configure
INFO: HHH000043:
Configuring from resource: /hibernate.cfg.xml
Jan 08, 2014 7:41:14
PM org.hibernate.cfg.Configuration getConfigurationInputStream
INFO: HHH000040:
Configuration resource: /hibernate.cfg.xml
Jan 08, 2014 7:41:15
PM org.hibernate.cfg.Configuration doConfigure
INFO: HHH000041:
Configured SessionFactory: null
Jan 08, 2014 7:41:15
PM
org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl
configure
INFO: HHH000402:
Using Hibernate built-in connection pool (not for production use!)
Jan 08, 2014 7:41:15
PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl
buildCreator
INFO: HHH000401:
using driver [com.mysql.jdbc.Driver] at URL
[jdbc:mysql://localhost:3306/northwind]
Jan 08, 2014 7:41:15
PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl
buildCreator
INFO: HHH000046:
Connection properties: {user=root, password=****}
Jan 08, 2014 7:41:15
PM
org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl
buildCreator
INFO: HHH000006:
Autocommit mode: false
Jan 08, 2014 7:41:15
PM
org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl
configure
INFO: HHH000115:
Hibernate connection pool size: 20 (min=1)
Jan 08, 2014 7:41:15
PM org.hibernate.dialect.Dialect <init>
INFO: HHH000400:
Using dialect: org.hibernate.dialect.MySQLDialect
Jan 08, 2014 7:41:15
PM org.hibernate.engine.jdbc.internal.LobCreatorBuilder
useContextualLobCreation
INFO: HHH000423:
Disabling contextual LOB creation as JDBC driver reported JDBC version [3]
less than 4
Jan 08, 2014 7:41:15
PM org.hibernate.engine.transaction.internal.TransactionFactoryInitiator
initiateService
INFO: HHH000399:
Using default transaction strategy (direct JDBC transactions)
Jan 08, 2014 7:41:15
PM org.hibernate.hql.internal.ast.ASTQueryTranslatorFactory <init>
INFO: HHH000397:
Using ASTQueryTranslatorFactory
FROM EmployeeBean
WHERE fName=:fName
Hibernate: select
employeebe0_.EmployeeID as Employee1_0_, employeebe0_.FirstName as
FirstNam2_0_, employeebe0_.LastName as LastName3_0_ from employees
employeebe0_ where employeebe0_.FirstName=?
[com.techcielo.hibernate43.bean.EmployeeBean@116639]
|
You can overwrite toString method to print
appropriate details of this bean.
Now to use Named native query we will use
following annotation in our Bean class. Note that in addition to name and query
we also need to tell hibernate that which class it need to use for storing
results returned by this query. J
@NamedNativeQueries(
{
@NamedNativeQuery(
name="get-emp-by-name-native",
query="SELECT *
FROM Employees WHERE firstName=:fName",
resultClass=EmployeeBean.class)
}
)
|
Now to use this native query we need to
change only parameter get-emp-by-name to get-emp-by-name-native. Hmm….thats all…run
the code J
Jan 08, 2014 7:52:49
PM org.hibernate.annotations.common.reflection.java.JavaReflectionManager
<clinit>
INFO: HCANN000001:
Hibernate Commons Annotations {4.0.4.Final}
Jan 08, 2014 7:52:49
PM org.hibernate.Version logVersion
INFO: HHH000412:
Hibernate Core {4.3.0.Final}
Jan 08, 2014 7:52:49
PM org.hibernate.cfg.Environment <clinit>
INFO: HHH000206:
hibernate.properties not found
Jan 08, 2014 7:52:49
PM org.hibernate.cfg.Environment buildBytecodeProvider
INFO: HHH000021:
Bytecode provider name : javassist
Jan 08, 2014 7:52:49
PM org.hibernate.cfg.Configuration configure
INFO: HHH000043:
Configuring from resource: /hibernate.cfg.xml
Jan 08, 2014 7:52:49
PM org.hibernate.cfg.Configuration getConfigurationInputStream
INFO: HHH000040:
Configuration resource: /hibernate.cfg.xml
Jan 08, 2014 7:52:49
PM org.hibernate.cfg.Configuration doConfigure
INFO: HHH000041:
Configured SessionFactory: null
Jan 08, 2014 7:52:49
PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl
configure
INFO: HHH000402:
Using Hibernate built-in connection pool (not for production use!)
Jan 08, 2014 7:52:49
PM
org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl
buildCreator
INFO: HHH000401:
using driver [com.mysql.jdbc.Driver] at URL
[jdbc:mysql://localhost:3306/northwind]
Jan 08, 2014 7:52:49
PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl
buildCreator
INFO: HHH000046:
Connection properties: {user=root, password=****}
Jan 08, 2014 7:52:49
PM
org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl
buildCreator
INFO: HHH000006:
Autocommit mode: false
Jan 08, 2014 7:52:49
PM
org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl
configure
INFO: HHH000115:
Hibernate connection pool size: 20 (min=1)
Jan 08, 2014 7:52:49
PM org.hibernate.dialect.Dialect <init>
INFO: HHH000400:
Using dialect: org.hibernate.dialect.MySQLDialect
Jan 08, 2014 7:52:49
PM org.hibernate.engine.jdbc.internal.LobCreatorBuilder
useContextualLobCreation
INFO: HHH000423:
Disabling contextual LOB creation as JDBC driver reported JDBC version [3]
less than 4
Jan 08, 2014 7:52:50
PM org.hibernate.engine.transaction.internal.TransactionFactoryInitiator
initiateService
INFO: HHH000399:
Using default transaction strategy (direct JDBC transactions)
Jan 08, 2014 7:52:50
PM org.hibernate.hql.internal.ast.ASTQueryTranslatorFactory <init>
INFO: HHH000397:
Using ASTQueryTranslatorFactory
SELECT * FROM
Employees WHERE firstName=:fName
Hibernate: SELECT *
FROM Employees WHERE firstName=?
[com.techcielo.hibernate43.bean.EmployeeBean@fde079]
|
The difference of these two approaches can be
seen in queries that are printed by SOP statements.
