Hibernate

映射文件<classname>.hbm.xml

<hibernate-mapping>
<class name="Employee" table="EMPLOYEE">
<id name="id" type="int" column="id">
<generator class="native"/>
</id>
<property name="firstName" column="first_name" type="string"/>
<property name="lastName" column="last_name" type="string"/>
<property name="salary" column="salary" type="int"/>
</class>
</hibernate-mapping>

映射类型

映射类型	Java 类型	ANSI SQL 类型
integer	int 或 java.lang.Integer	INTEGER
long	long 或 java.lang.Long	BIGINT
short	short 或 java.lang.Short	SMALLINT
float	float 或 java.lang.Float	FLOAT
double	double 或 java.lang.Double	DOUBLE
big_decimal	java.math.BigDecimal	NUMERIC
character	java.lang.String	CHAR(1)
string	java.lang.String	VARCHAR
byte	byte 或 java.lang.Byte	TINYINT
boolean	boolean 或 java.lang.Boolean	BIT
yes/no	boolean 或 java.lang.Boolean	CHAR(1) ('Y' or 'N')
true/false	boolean 或 java.lang.Boolean	CHAR(1) ('T' or 'F')

映射类型	Java 类型	ANSI SQL 类型
date	java.util.Date 或 java.sql.Date	DATE
time	java.util.Date 或 java.sql.Time	TIME
timestamp	java.util.Date 或 java.sql.Timestamp	TIMESTAMP
calendar	java.util.Calendar	TIMESTAMP
calendar_date	java.util.Calendar	DATE

映射类型	Java 类型	ANSI SQL 类型
binary	byte[]	VARBINARY (or BLOB)
text	java.lang.String	CLOB
serializable	any Java class that implements java.io.Serializable	VARBINARY (or BLOB)
clob	java.sql.Clob	CLOB
blob	java.sql.Blob	BLOB

映射类型	Java 类型	ANSI SQL 类型
class	java.lang.Class	VARCHAR
locale	java.util.Locale	VARCHAR
timezone	java.util.TimeZone	VARCHAR
currency	java.util.Currency	VARCHAR

新增

SessionFactory factory = new Configuration().configure().buildSessionFactory();
Session session = factory.openSession();
Transaction tx = null;
Integer employeeID = null;
try{
tx = session.beginTransaction();
Employee employee = new Employee(fname, lname, salary);
employeeID = (Integer) session.save(employee);
tx.commit();
}catch (HibernateException e) {
if (tx!=null) tx.rollback();
e.printStackTrace();
}finally {
session.close();
}

查询

session.createQuery("FROM Employee").list();

更新

Employee employee = (Employee)session.get(Employee.class, EmployeeID);
employee.setSalary( salary );
session.update(employee);

删除

Employee employee = (Employee)session.get(Employee.class, EmployeeID);
session.delete(employee);

注解

@Entity
@Table(name = "EMPLOYEE")
public class Employee {
@Id @GeneratedValue
@Column(name = "id")
private int id;

@Column(name = "first_name")
private String firstName;

@Column(name = "last_name")
private String lastName;

@Column(name = "salary")
private int salary;

HQL

HQL是一种面向对象的查询语言，类似于 SQL，但不是去对表和列进行操作，而是面向对象和它们的属性。
String hql = "SELECT E.firstName FROM Employee E WHERE E.id > 10 ORDER BY E.salary DESC";
Query query = session.createQuery(hql);
List results = query.list();

HQL 查询功能支持命名参数。既能接受来自用户的简单输入，又无需防御 SQL 注入攻击。
String hql = "FROM Employee E WHERE E.id = :employee_id";
Query query = session.createQuery(hql);
query.setParameter("employee_id",10);
List results = query.list();

更新/删除

String hql = "UPDATE Employee set salary = :salary WHERE id = :employee_id";
Query query = session.createQuery(hql);
query.setParameter("salary", 1000);
query.setParameter("employee_id", 10);
int result = query.executeUpdate();
String hql = "DELETE FROM Employee WHERE id = :employee_id";
Query query = session.createQuery(hql);
query.setParameter("employee_id", 10);
int result = query.executeUpdate();

分页

String hql = "FROM Employee";
Query query = session.createQuery(hql);
query.setFirstResult(1);
query.setMaxResults(10);
List results = query.list();

原生 SQL

createSQLQuery
String sql = "SELECT * FROM EMPLOYEE";
SQLQuery query = session.createSQLQuery(sql);
query.addEntity(Employee.class);
List results = query.list();