hibernate范例简析-hibernate_hql（二）

hibernate实例简析-hibernate_hql（二）

?

1、条件查询【重要】?
?* 可以采用拼字符串的方式传递参数
?* 可以采用 ？来传递参数（索引从0开始）
?* 可以采用 :参数名 来传递参数
?* 如果传递多个参数，可以采用setParamterList方法
?* 在hql中可以使用数据库的函数，如：date_format
?参见：SimpleConditionQueryTest.java

SimpleConditionQueryTest

List students = session.createQuery("select s.id, s.name from Student s where s.name like '%1%'").list();
???for (Iterator iter=students.iterator(); iter.hasNext();) {
????Object[] obj = (Object[])iter.next();
????System.out.println(obj[0] + "," + obj[1]);
???}

?

====

List students = session.createQuery("select s.id, s.name from Student s where s.name like ?")
????????? ?????.setParameter(0, "%1%")
????????? ?????.list();
???
???for (Iterator iter=students.iterator(); iter.hasNext();) {
????Object[] obj = (Object[])iter.next();
????System.out.println(obj[0] + "," + obj[1]);
???}

=====

List students = session.createQuery("select s.id, s.name from Student s where s.name like :myname")
????????? ?????.setParameter("myname", "%1%")
????????? ?????.list();
???
???for (Iterator iter=students.iterator(); iter.hasNext();) {
????Object[] obj = (Object[])iter.next();
????System.out.println(obj[0] + "," + obj[1]);
???}

====

List students = session.createQuery("select s.id, s.name from Student s where s.name like :myname and s.id=:myid")
????????? ?????.setParameter("myname", "%1%")
????????? ?????.setParameter("myid", 12)
????????? ?????.list();
???
???for (Iterator iter=students.iterator(); iter.hasNext();) {
????Object[] obj = (Object[])iter.next();
????System.out.println(obj[0] + "," + obj[1]);
???}

====

List students = session.createQuery("select s.id, s.name from Student s where s.id in(:myids)")
?????????.setParameterList("myids", new Object[]{1, 2, 3, 4, 5})
????????? ?????.list();
???
???for (Iterator iter=students.iterator(); iter.hasNext();) {
????Object[] obj = (Object[])iter.next();
????System.out.println(obj[0] + "," + obj[1]);
???}

===

List students = session.createQuery("select s.id, s.name from Student s where date_format(s.createTime, '%Y-%m')=?")
?????????.setParameter(0, "2008-02")
????????? ?????.list();
???for (Iterator iter=students.iterator(); iter.hasNext();) {
????Object[] obj = (Object[])iter.next();
????System.out.println(obj[0] + "," + obj[1]);
???}

===

SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
???
???List students = session.createQuery("select s.id, s.name from Student s where s.createTime between ? and ?")
?????????.setParameter(0, sdf.parse("2008-01-10 00:00:00"))
?????????.setParameter(1, sdf.parse("2008-02-15 23:59:59"))
????????? ?????.list();
???for (Iterator iter=students.iterator(); iter.hasNext();) {
????Object[] obj = (Object[])iter.next();
????System.out.println(obj[0] + "," + obj[1]);
???}

?

2、分页查询【重要】?
?* setFirstResult()，从0开始
?* setMaxResults,每页显示多少条数据
?参见：PageQueryTest.java

List students = session.createQuery("from Student")
?????????.setFirstResult(1)
?????????.setMaxResults(2)
?????????.list();
???for (Iterator iter=students.iterator(); iter.hasNext();) {
????Student student = (Student)iter.next();
????System.out.println(student.getName());
???}