繼續(xù)之前那個(gè)復(fù)習(xí)，繼續(xù)那3張表，在此前已經(jīng)可以聯(lián)級(jí)插入數(shù)據(jù)，現(xiàn)在來聯(lián)級(jí)檢索出3張表的數(shù)據(jù)，假設(shè)要求查出名字為“lzj"的學(xué)生在3張表里的所有記錄。使用inner join操作。
TstudentDAO：
public List findall(String name){
Session session =this.getSession();
Transaction tx = null;
Query query = session.createQuery("select t.name,t.email,s.name,tt.times from TStudent t join t.TSubjectses s join t.TTests tt where t.name=:name");
query.setString("name", name);
List result = query.list();
List templist = new ArrayList();
for (Iterator it = result.iterator();it.hasNext();){
Object[] row=(Object[])it.next();
Map mm = new HashMap();
mm.put("name", (String)row[0]);
mm.put("email", (String)row[1]);
mm.put("sname", (String)row[2]);
mm.put("times", (Integer)row[3]);
templist.add(mm);
}
return templist;
}
action里只需要一句話：
List results = tstudentDAO.findall("lzj");
并將結(jié)果返回給struts的jsp頁面：
if(results!=null){
HttpSession session=request.getSession();
session.setAttribute("results",results);
return mapping.findForward("ok");
jsp頁面接受，使用struts標(biāo)簽：
<logic:present name="results">
<table border="1">
<logic:iterate id="element" name="results">
<tr>
<td width="100"><bean:write name="element" property="name"/></td>
<td width="100"><bean:write name="element" property="email"/></td>
<td width="100"><bean:write name="element" property="sname"/></td>
<td width="100"><bean:write name="element" property="times"/></td>
<td id="result"></td>
</tr>
</logic:iterate>
</logic:present>