I have some simple code that is supposed to select all teacher objects from a table of teachers in my mysql database. When I run similar queries for other domain objects, it is extremely fast, but for some reason this query takes forever. Also if I run a select all query from mysql workbench it executes instantly, so I think the problem is with my hibernate mapping. There are only 30 ish entries in the table so there is no reason this should be taking long.
Hibernate mapping xml file:
<hibernate-mapping>
<class name="org.myschool.domain.Teacher" table="teacher">
<id name="teacher_id" type="java.lang.Integer">
<column name="teacher_id" />
<generator class="increment" />
</id>
<property name="firstName" type="java.lang.String">
<column name="first_name" length="20" not-null="true"/>
</property>
<property name="lastName" type="java.lang.String">
<column name="last_name" length="30" not-null="true" />
</property>
<property name="middleInitial" type="java.lang.String">
<column name="middle_initial" length="1" not-null = "false"/>
</property>
<set name="wantsCourses" table="teacher_want" inverse="false" lazy="true" fetch="select" cascade="all">
<key>
<column name="teacher_id" not-null="true" />
</key>
<many-to-many entity-name="org.myschool.domain.Course">
<column name="course_id" not-null="true" />
</many-to-many>
</set>
<set name="eligibleCourses" table="teacher_eligible" inverse="false" lazy="true" fetch="select" cascade="all">
<key>
<column name="teacher_id" not-null="true" />
</key>
<many-to-many entity-name="org.myschool.domain.Course">
<column name="course_id" not-null="true" />
</many-to-many>
</set>
<set name="teacherTranscript" table="assigned_course" inverse="true" lazy="true" fetch="select">
<key>
<column name="teacher_id" not-null="true" />
</key>
<one-to-many class="org.myschool.domain.AssignedCourse" />
</set>
</class>
</hibernate-mapping>
This is the method being called that takes so long :
public List<Teacher> findAll() {
try {
#SuppressWarnings("unchecked")
List<Teacher> results = (List<Teacher>) sessionFactory.getCurrentSession()
.createCriteria("org.myschool.domain.Teacher").list();
log.debug("find all successful, result size: " + results.size());
return results;
} catch (RuntimeException re) {
log.error("find all failed", re);
throw re;
}
}
And this is the actual hibernate query being executed:
Hibernate: select this_.teacher_id as teacher_1_8_0_, this_.first_name as first_na2_8_0_, this_.last_name as last_nam3_8_0_, this_.middle_initial as middle_i4_8_0_ from teacher this_
Here's the sql command that makes the teacher table:
CREATE TABLE teacher(
teacher_id INT(6) UNSIGNED NOT NULL PRIMARY KEY,
first_name VARCHAR(20) NOT NULL,
middle_initial CHAR(1),
last_name VARCHAR(30) NOT NULL)
Thanks for your help!
Related
I am getting following issue while saving entity in hibernate -
It duplicates the record with null values -
(2661956,2601555,'Chloe','Chloe','Thooks',null,null,null,null,null,null,'Y','N','XYZ',to_date('15-NOV-16','DD-MON-RR'),null,null)
with a duplicate -
(2661946,2601555,null,null,null,null,null,null,null,null,null,'Y','N','XYZ',to_date('15-NOV-16','DD-MON-RR'),null,null) -
We have the following mapping -
Parent -
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping default-lazy="false">
<class name="com.sm.persistence.LOADetailBO" table="LOADETAILS">
<id name="loaDetailsId" type="long">
<column name="LOA_ID" precision="38" scale="0"/>
<generator class="com.sm.persistence.dao.seqgen.LOADetailSeqGen">
</generator>
</id>
<many-to-one name="reregistration" class="com.sm.persistence.RerBO" fetch="join">
<column name="RER_ID" precision="38" scale="0"/>
</many-to-one>
<property name="relatedPlanManager" type="string">
<column name="RELATED_PLAN_MANAGER"/>
</property>
<property name="relatedPlanManagerCode" type="string">
<column name="RELATED_PLAN_MANAGER_CODE"/>
</property>
<set name="relatedPlanManagerAddress" inverse="true" cascade="all-delete-orphan">
<key>
<column name="LOA_ID" precision="38" scale="0" not-null="false"/>
</key>
<one-to-many class="com.sm.persistence.AddressBO" />
</set>
<set name="corporateCustomers" inverse="true" cascade="all-delete-orphan">
<key>
<column name="LOA_ID" precision="38" scale="0" not-null="false"/>
</key>
<one-to-many class="com.sm.persistence.CorporateCustomerBO" />
</set>
<set name="privateCustomers" inverse="true" cascade="all-delete-orphan">
<key>
<column name="LOA_ID" precision="38" scale="0" not-null="false" />
</key>
<one-to-many class="com.sm.persistence.PrivateCustomerBO"/>
</set>
<set name="unwrappedAccount" inverse="true" cascade="all-delete-orphan">
<key>
<column name="LOA_ID" precision="38" scale="0" not-null="false"/>
</key>
<one-to-many class="com.sm.persistence.UnwrappedAccountBO" />
</set>
<set name="wrappedAccount" inverse="true" cascade="all-delete-orphan">
<key>
<column name="LOA_ID" precision="38" scale="0" not-null="false" />
</key>
<one-to-many class="com.sm.persistence.WrappedAccountBO"/>
</set>
</class>
</hibernate-mapping>
Child -
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping default-lazy="false">
<class name="com.sm.persistence.PrivateCustomerBO" table="RER_CUSTOMER_DETAIL">
<id name="privateCustomerId" type="long">
<column name="RERE_CUSTOMER_ID" precision="38" scale="0"/>
<generator class="com.sm.persistence.dao.seqgen.PrivateCustomerSeqGen">
</generator>
</id>
<many-to-one name="loaDetail" class="com.sm.persistence.LOADetailBO" fetch="join">
<column name="LOA_DETAILS_ID" precision="38" scale="0"/>
</many-to-one>
<property name="title" type="string">
<column name="TITLE"/>
</property>
<property name="firstName" type="string">
<column name="FIRST_NAME"/>
</property>
<property name="surname" type="string">
<column name="SURNAME"/>
</property>
<set name="address" inverse="false" cascade="all-delete-orphan">
<key>
<column name="PRIVATE_CUSTOMER_ID" precision="38" scale="0" not-null="false"/>
</key>
<one-to-many class="com.sm.persistence.AddressBO" />
</set>
<property name="primary" type="string">
<column name="IS_PRIMARY"/>
</property>
<property name="corporate" type="string">
<column name="IS_CORPORATE"/>
</property>
<!--<property name="dateofBirth" type="string">
<column name="DATE_OF_BIRTH"/>
</property>-->
<property name="nationalInsurance" type="string">
<column name="NINO"/>
</property>
</class>
</hibernate-mapping>
I checked parent object both pre and post save and can't find any object with null value populated. However, when I fetch the object hierarchy with criteria api it returns duplicate record with null.
Please guide.
Quick answer:
PrivateCustomerBO is a child of LOADetailBO. So when your java code
saves a PrivateCustomerBO object it will write to all tables
specified against these 2 objects: RER_CUSTOMER_DETAIL = primary
table for PrivateCustomerBO, LOADETAILS = primary table for
LOADetailBO, plus all tables referenced by these two objects via
many-to-one or one-to-many mappings. CORRECT BEHAVIOUR
Expanding the bolded bit above, LOADetailBO is referenced by
PrivateCustomerBO via:
<many-to-one name="loaDetail" class="com.sm.persistence.LOADetailBO" fetch="join">
<column name="LOA_DETAILS_ID" precision="38" scale="0"/>
</many-to-one>
This means that LOADETAILS is additionally referenced as a related
table, not just a parent and a second row is written (in this case
there is some data missing (NULL) because your program hasn't
populated it for the referenced entity). INCORRECT BEHAVIOUR.
Fix: remove the many-to-one mapping shown above (it's redundant and covered by parent).
Hibernate is giving me the following exception
org.hibernate.MappingException: Repeated column in mapping for entity: Pricelist column: ID_OFFER (should be mapped with insert="false" update="false")
but I really cannot find the duplicate reference to ID_OFFER. Here they are the two mapping files involved.
Offer.hbm.xml
<hibernate-mapping>
<class name="Offer" table="OFFERS">
<id name="idOffer" type="java.lang.Long">
<column name="ID_OFFER" not-null="true" precision="10" scale="0"
sql-type="NUMBER" unique="true"/>
<generator class="native">
<param name="sequence">OFFERS_SEQ</param>
</generator>
</id>
<property generated="never" lazy="false" name="name" type="string">
<column name="name" not-null="true" sql-type="VARCHAR2" unique="true"/>
</property>
<set name="pricelists" sort="unsorted" table="PRICELISTS">
<key not-null="true">
<column name="ID_OFFER" not-null="true" precision="10" scale="0" sql-type="NUMBER"/>
</key>
<one-to-many class="Pricelist"/>
</set>
</class>
</hibernate-mapping>
Pricelist.hbm.xml
<hibernate-mapping>
<class name="Pricelist" table="PRICELISTS">
<id name="idPricelist" type="java.lang.Long">
<column name="ID_PRICELIST" not-null="true" precision="10" scale="0" sql-type="NUMBER"/>
<generator class="native">
<param name="sequence">PRICELISTS_SEQ</param>
</generator>
</id>
<property name="name" type="string">
<column length="255" name="NAME" not-null="true" sql-type="VARCHAR2"/>
</property>
<property name="versionMajor" type="integer">
<column name="VERSION_MAJOR" not-null="true" precision="5" scale="0" sql-type="NUMBER"/>
</property>
<property name="versionMinor" type="integer">
<column name="VERSION_MINOR" not-null="true" precision="5" scale="0" sql-type="NUMBER"/>
</property>
<many-to-one class="Offer" name="offer">
<column name="ID_OFFER" not-null="true" precision="10" scale="0" sql-type="NUMBER"/>
</many-to-one>
<many-to-one class="PricelistStatus" name="status">
<column name="ID_STATUS_PRICELIST" not-null="true" precision="10"
scale="0" sql-type="NUMBER"/>
</many-to-one>
<property name="validFrom" type="calendar">
<column name="INIT_TIMESTAMP" not-null="true" scale="6" sql-type="TIMESTAMP"/>
</property>
<property name="validUntil" type="calendar">
<column name="END_TIMESTAMP" not-null="false" scale="6" sql-type="TIMESTAMP"/>
</property>
</class>
</hibernate-mapping>
I am going crazy. Can anybody see where is it supposed to be duplicated the reference to the column ID_OFFER? Please note: two tables of my schema have a column named like that: OFFERS.ID_OFFER, which is the primary key of the table OFFERS and PRICELIST.ID_OFFER which has a foreign key constraint referencing, obviously, OFFERS.ID_OFFER.
You forgot about map this column as owning side (Offer.hbm.xml file)
<set name="pricelists" sort="unsorted" table="PRICELISTS">
<key not-null="true">
<column name="ID_OFFER" not-null="true" precision="10" scale="0" sql-type="NUMBER"/>
</key>
<one-to-many class="Pricelist"/>
</set>
it should look like (look at inverse="true"):
<set name="pricelists" sort="unsorted" table="PRICELISTS" inverse="true">
<key not-null="true">
<column name="ID_OFFER" not-null="true" precision="10" scale="0" sql-type="NUMBER"/>
</key>
<one-to-many class="Pricelist"/>
</set>
What #zxcf said, actually made the exception disappear, but made another question appear in my mind. Why doesn't the following mapping creates the same problem?
ServiceElement.hbm.xml
<hibernate-mapping>
<class name="ServiceElement" table="SERVICE_ELEMENTS">
<id name="idServiceElement" type="java.lang.Long">
<column name="ID_SERVICE_ELEMENT" not-null="true" precision="10"
scale="0" sql-type="NUMBER" unique="true"/>
<generator class="native">
<param name="sequence">SERVICE_ELEMENTS_SEQ</param>
</generator>
</id>
<set name="prices" table="PRICES">
<key>
<column name="ID_SERVICE_ELEMENT" not-null="true" precision="10"
scale="0" sql-type="NUMBER"/>
</key>
<one-to-many class="Price"/>
</set>
</class>
</hibernate-mapping>
Price.hbm.xml
<hibernate-mapping>
<class name="Price" table="PRICES">
<id name="idPrice" type="java.lang.Long">
<column name="ID_PRICE" not-null="true" precision="10" scale="0"
sql-type="NUMBER" unique="true"/>
<generator class="native">
<param name="sequence">PRICES_SEQ</param>
</generator>
</id>
<many-to-one class="ServiceElement" name="serviceElement">
<column name="ID_SERVICE_ELEMENT" not-null="true" precision="10"
scale="0" sql-type="NUMBER"/>
</many-to-one>
</class>
</hibernate-mapping>
Isn't it the exact same mapping? But it does not throw any exception. Here they go the DDLs:
CREATE TABLE "CE_PRICELIST"."OFFERS"
( "ID_OFFER" NUMBER(10,0),
"NAME" VARCHAR2(255 CHAR));
CREATE UNIQUE INDEX "CE_PRICELIST"."OFFERS_PK" ON "CE_PRICELIST"."OFFERS" ("ID_OFFER");
ALTER TABLE "CE_PRICELIST"."OFFERS" ADD CONSTRAINT "OFFERS_PK" PRIMARY KEY ("ID_OFFER");
CREATE TABLE "CE_PRICELIST"."PRICELISTS"
( "ID_PRICELIST" NUMBER(10,0),
"ID_OFFER" NUMBER(10,0));
CREATE UNIQUE INDEX "CE_PRICELIST"."PRICELISTS_PK" ON "CE_PRICELIST"."PRICELISTS" ("ID_PRICELIST");
ALTER TABLE "CE_PRICELIST"."PRICELISTS" ADD CONSTRAINT "PRICELISTS_PK" PRIMARY KEY ("ID_PRICELIST");
ALTER TABLE "CE_PRICELIST"."PRICELISTS" ADD CONSTRAINT "PRICELISTS_OFFER_ID_FK" FOREIGN KEY ("ID_OFFER") REFERENCES "CE_PRICELIST"."OFFERS" ("ID_OFFER") ENABLE;
CREATE TABLE "CE_PRICELIST"."SERVICE_ELEMENTS"
( "ID_SERVICE_ELEMENT" NUMBER(10,0));
CREATE UNIQUE INDEX "CE_PRICELIST"."SERVICE_ELEMENTS_PK" ON "CE_PRICELIST"."SERVICE_ELEMENTS" ("ID_SERVICE_ELEMENT");
ALTER TABLE "CE_PRICELIST"."SERVICE_ELEMENTS" ADD CONSTRAINT "SERVICE_ELEMENTS_PK" PRIMARY KEY ("ID_SERVICE_ELEMENT");
CREATE TABLE "CE_PRICELIST"."PRICES"
( "ID_PRICE" NUMBER(10,0),
"ID_SERVICE_ELEMENT" NUMBER(10,0));
CREATE UNIQUE INDEX "CE_PRICELIST"."PRICES_PK" ON "CE_PRICELIST"."PRICES" ("ID_PRICE");
ALTER TABLE "CE_PRICELIST"."PRICES" ADD CONSTRAINT "PRICES_SERVICE_ELEMENT_ID_FK" FOREIGN KEY ("ID_SERVICE_ELEMENT")
REFERENCES "CE_PRICELIST"."SERVICE_ELEMENTS" ("ID_SERVICE_ELEMENT") ENABLE;
OFFERS has a PK on ID_OFFER, which is referenced by PRICELISTS.ID_OFFER; Offer has a Set< Pricelist >;
SERVICE_ELEMENTS has a PK on ID_SERVICE_ELEMENT, which is referenced by PRICES.ID_SERVICE_ELEMENT; ServiceElement has a Set< Price >;
So why is the inverse attribute needed in one case and not in another one?
I have two tables stock and category having many-to-many relationship each other.
Stock.hbm.xml
<hibernate-mapping>
<class name="hibernate.mapping.manytomany.Stock" table="stock">
<id name="stockId" type="java.lang.Integer">
<column name="STOCK_ID" />
<generator class="identity" />
</id>
<property name="stockCode" type="string">
<column name="STOCK_CODE" length="10" not-null="true" unique="true" />
</property>
<property name="stockName" type="string">
<column name="STOCK_NAME" length="20" not-null="true" unique="true" />
</property>
<set name="categories" table="stock_category"
inverse="false" lazy="true" fetch="select" cascade="all" >
<key>
<column name="STOCK_ID" not-null="true" />
</key>
<many-to-many entity-name="hibernate.mapping.manytomany.Category">
<column name="CATEGORY_ID" not-null="true" />
</many-to-many>
</set>
</class>
</hibernate-mapping>
Category.hbm.xml
<hibernate-mapping>
<class name="hibernate.mapping.manytomany.Category" table="category">
<id name="categoryId" type="java.lang.Integer">
<column name="CATEGORY_ID" />
<generator class="identity" />
</id>
<property name="name" type="string">
<column name="NAME" length="10" not-null="true" />
</property>
<property name="desc" type="string">
<column name="[DESC]" not-null="true" />
</property>
<set name="stocks" table="stock_category" inverse="true" lazy="true"
fetch="select">
<key>
<column name="CATEGORY_ID" not-null="true" />
</key>
<many-to-many entity-name="hibernate.mapping.manytomany.Stock">
<column name="STOCK_ID" not-null="true" />
</many-to-many>
</set>
</class>
</hibernate-mapping>
And this is my criteria query,
Criteria c = session.createCriteria(Category.class, "c");
c.createAlias("c.stocks", "s");
c.add(Restrictions.eq("c.categoryId", 1));
c.setProjection(Projections.projectionList()
.add(Projections.property("s.stockId"))
.add(Projections.property("s.stockName")));
I need equivalent HQL for this scenario..I've tried this but it gives different result,
String query = "select c.stocks.stockId, c.stocks.stockName from Category c where
c.categoryId=1"
Let me know if you need more details.
OK, so apparently, you missed the section about joins in the documentation:
select s.stockId, // equivalent to the s.stockId projection
s.stockName // equivalent to the s.stockName projection
from Category c // equivalent to the root criteria creation
join c.stocks s // equivalent to the alias creation
where c.categoryId = 1 // equivalent to the restriction addition
I am planning to investigate this issue thoroughly. What i doubt from previous answer for now is there should be ON Clause in join statement. Pardon me if my expectation is wrong.
select s.stockId,s.stockName from Category c join c.stocks s
on c.stockId=s.stockId where c.categoryId = 1 ;
//it might be on c.CATEGORY_ID=s.CATEGORY_ID also
I am trying to map two tables using hibernate one-to-many mapping. But, always it is mapping with the wrong column. Please any body help me on this.
Level4_Master [level_id (PK/Auto Increament), company_id, level_name, next_level_id, ts]
Level3_Master [level_id (PK/Auto Increament), prv_level_id, level_name, next_level_id, ts]
Above are the two tables I am using for the mapping. Here, I wanted to map column next_level_id of Level4_Master with column prv_level_id of Level3_Master. But, hibernate always mapping the column prv_level_id with level_id of Level4_Master as FK. My mapping files are:
<hibernate-mapping>
<class name="com.pojo.Level4" table="Level4_Master">
<id name="levelId" type="java.lang.Integer">
<column name="level_id" />
<generator class="increment" />
</id>
<property name="companyId" >
<column name="company_id" length="10" not-null="true" unique="true" />
</property>
<property name="levelName">
<column name="level_name" length="20" not-null="true" unique="true" />
</property>
<property name="nextLevelId" type="java.lang.Integer">
<column name="next_level_id" />
</property>
<set name="levelList" table="Level3_Master" inverse="true" lazy="true" fetch="select">
<key>
<column name="prv_level_id" not-null="true" />
</key>
<one-to-many class="com.pojo.Level3" />
</set>
</class>
</hibernate-mapping>
and
<hibernate-mapping>
<class name="com.pojo.Level3" table="Level3_Master">
<id name="levelId" type="java.lang.Integer">
<column name="level_id" />
<generator class="increment" />
</id>
<property name="prvLevelId" >
<column name="prv_level_id" length="10" not-null="true" unique="true" />
</property>
<property name="levelName">
<column name="level_name" length="20" not-null="true" unique="true" />
</property>
<property name="nextLevelId" type="java.lang.Integer">
<column name="next_level_id" />
</property>
<set name="levelList" table="Level2_Master" inverse="true" lazy="true" fetch="select">
<key>
<column name="prv_level_id" not-null="true" />
</key>
<one-to-many class="com.pojo.Level2" />
</set>
</class>
</hibernate-mapping>
and my pojo classes are like
class Level4{
private int levelId;
private int companyId;
private String levelName;
private int nextLevelId;
private Set<Level3> levelList = new HashSet<Level3>(0);
private Timestamp ts;
//getter n setter
}
class Level3{
private int levelId;
private int prvLevelId;
private String levelName;
private int nextLevelId;
private Set<Level2> levelList = new HashSet<Level2>(0);
private Timestamp ts;
//getter n setter
}
You need to use property-ref attribute with the property name. The property must add unique="true" in the property mapping.
Example -
<hibernate-mapping><class name="com.pojo.Level4" table="Level4_Master">
<id name="levelId" type="java.lang.Integer">
<column name="level_id" />
<generator class="increment" />
</id>
<property name="companyId" >
<column name="company_id" length="10" not-null="true" unique="true" />
</property>
<property name="levelName">
<column name="level_name" length="20" not-null="true" unique="true" />
</property>
<property name="nextLevelId" type="java.lang.Integer" unique="true">
<column name="next_level_id" />
</property>
<set name="levelList" table="Level3_Master" inverse="true" lazy="true" fetch="select">
<key>
<column name="prv_level_id" not-null="true" property-ref="nextLevelId"/>
</key>
<one-to-many class="com.pojo.Level3" />
</set>
I have two tables as below.
"User Acc" is user's profile details and user's login details(username password) are in a seperate table called login.When I generated the entities in Netbeans IDE, there were 2 tables for login(database) table. One generated entity is "Login", another one is "LoginId".Login entity has a reference to LoginId and UserAcc entity. LoginId entity has username and password which were in login database table.UserAcc has primary key which is INT for each user.That key is the foreign key of login table.
Now I want to check the user # loging. How I do is, I create a LoginId instance and set the user name and password and then check any object which has same LoginId. Here is the code.
uName and pw are strings and taken from user input.
LoginId id=new LoginId(uName, pw);
Session ses = NewHibernateUtil.getSessionFactory().openSession();
Criteria crit = ses.createCriteria(Login.class);
crit.add(Restrictions.eq("id", id));
Entities.Login log = (Entities.Login)crit.uniqueResult();
But eventhough there are existing usernames and passwords matching with given username and password, the log is always null.
Any one tell me where I should check and what the problem is. Thank you.
And my other problem is why a separate entity("LoginId") is created for two columns(primary keys) in one database table and another entity for that its database table .
for login;
<hibernate-mapping>
<class name="Entities.Login" table="login" catalog="pcw">
<composite-id name="id" class="Entities.LoginId">
<key-property name="uname" type="string">
<column name="uname" length="10" />
</key-property>
<key-property name="pw" type="string">
<column name="pw" length="10" />
</key-property>
</composite-id>
<many-to-one name="useracc" class="Entities.Useracc" fetch="select">
<column name="UserAcc_uid" not-null="true" />
</many-to-one>
</class>
for UserAcc:
<hibernate-mapping>
<class name="Entities.Useracc" table="useracc" catalog="pcw">
<id name="uid" type="java.lang.Integer">
<column name="uid" />
<generator class="identity" />
</id>
<property name="fname" type="string">
<column name="fname" length="45" />
</property>
<property name="sname" type="string">
<column name="sname" length="45" />
</property>
<property name="RDate" type="date">
<column name="r_date" length="10" />
</property>
<property name="street" type="string">
<column name="street" length="45" />
</property>
<property name="city" type="string">
<column name="city" length="45" />
</property>
<property name="email" type="string">
<column name="email" length="45" />
</property>
<property name="tel" type="string">
<column name="tel" length="45" />
</property>
<set name="comments" inverse="true" cascade="all">
<key>
<column name="UserAcc_uid" not-null="true" />
</key>
<one-to-many class="Entities.Comment" />
</set>
<set name="logins" inverse="true" cascade="all">
<key>
<column name="UserAcc_uid" not-null="true" />
</key>
<one-to-many class="Entities.Login" />
</set>
</class>
Anyway you can use HQL to solve it it will look more and less like this:
public boolean authenticate(Sting username,String pass){
Session ses = NewHibernateUtil.getSessionFactory().openSession();
String sql = "from Login login where login.username:= username and login.pass = :=pass";
Query query = session.createQuery(sql);
query.setString("username",username);
query.setString("pass",pass);
List<Login> result = query.list();
//close session, transaction,etc....
if (result ==null)
return false;
else
return true;
}