渚嬪瓙錛?br />
<class name="User" table="USER">
<composite-id name="userId" class="UserId">
<key-property name="userName"
column="USERNAME"/>
<key-property name="organizationId"
column="ORGANIZATION_ID"/>
</composite-id>
<version name="version"
column="VERSION"
unsaved-value="0"/>
<many-to-one name="organization"
class="Organization"
column="ORGANIZATION_ID"
insert="false" update="false"/>
...
</class>
public class UserId extends Serializable {
private String username;
private String organizationId;
public UserId(String username, String organizationId) {
this.username = username;
this.organizationId = organizationId;
}
// Getters...
public boolean equals(Object o) {
if (this == o) return true;
if (o = null) return false;
if (!(o instanceof UserId)) return false;----涓鑸殑鍒ゆ柇寮澶撮兘鍩烘湰榪欐牱鍐?/span>
final UserId userId = (UserId) o;
if (!organizationId.equals(userId.getOrganizationId()))
return false;
if (!username.equals(userId.getUsername()))
return false;
return true;
}
public int hashCode() {
return username.hashCode();
)
}
浣跨敤濡備笅錛?br />
UserId id = new UserId("john", 42);
User user = new User();
// Assign a primary key value
user.setUserId(id);
// Set property values
user.setFirstname("John");
user.setLastname("Doe");
session.saveOrUpdate(user); // will save, since version is 0
session.flush();
]]>
where item.description like '%gc%'
and bid.amount > 100
榪欐牱寰楀嚭鏉ョ殑鏄袱涓璞?br /> item 鍜宐id
閫氳繃榪欐牱榪涜鏌ヨ
Query q = session.createQuery("from Item item join item.bids bid");
Iterator pairs = q.list().iterator();
Joining associations 263
while ( pairs.hasNext() ) {
Object[] pair = (Object[]) pairs.next();
Item item = (Item) pair[0];
Bid bid = (Bid) pair[1];
}
濡傛灉鏄?br /> select item
from Item item
join item.bids bid
where item.description like '%gc%'
and bid.amount > 100
閭ｄ箞鍙緱鍑虹殑鏄竴涓璞?
]]>
1銆傜珛鍗沖姞杞?br /> 2銆傚歡榪熷姞杞?br /> 3銆傞鍏堝姞杞?br /> 4銆傛壒閲忓姞杞?br />
瀵逛簬寤惰繜鍔犺澆鍙互璁劇疆lazy="true"
瀵逛簬棰勫厛鍔犺澆鍙互鍦℉QL涓嬌鐢╫ut join 鎴栬呬嬌鐢╨eft join fetch XXX錛屼嬌鍏跺姞杞?br />
]]>
鐢眓ew鍛戒護寮杈熷唴瀛樼┖闂寸殑java瀵硅薄錛?/p>
eg. Person person = new Person("amigo", "濂?);
濡傛灉娌℃湁鍙橀噺瀵硅瀵硅薄榪涜寮曠敤錛屽畠灝嗚java铏氭嫙鏈哄洖鏀躲?/p>
鐬椂瀵硅薄鍦ㄥ唴瀛樺绔嬪瓨鍦紝瀹冩槸鎼哄甫淇℃伅鐨勮澆浣擄紝涓嶅拰鏁版嵁搴撶殑鏁版嵁鏈変換浣曞叧鑱斿叧緋伙紝鍦℉ibernate涓紝鍙氳繃session鐨剆ave()鎴杝aveOrUpdate()鏂規硶灝嗙灛鏃跺璞′笌鏁版嵁搴撶浉鍏寵仈錛屽茍灝嗘暟鎹搴旂殑鎻掑叆鏁版嵁搴撲腑錛屾鏃惰鐬椂瀵硅薄杞彉鎴愭寔涔呭寲瀵硅薄銆?/p>
- 鎸佷箙鎬?/strong>
澶勪簬璇ョ姸鎬佺殑瀵硅薄鍦ㄦ暟鎹簱涓叿鏈夊搴旂殑璁板綍錛屽茍鎷ユ湁涓涓寔涔呭寲鏍囪瘑銆傚鏋滄槸鐢╤ibernate鐨刣elete()鏂規硶錛屽搴旂殑鎸佷箙瀵硅薄灝卞彉鎴愮灛鏃跺璞★紝鍥犳暟鎹簱涓殑瀵瑰簲鏁版嵁宸茶鍒犻櫎錛岃瀵硅薄涓嶅啀涓庢暟鎹簱鐨勮褰曞叧鑱斻?/p>
褰撲竴涓猻ession鎵цclose()鎴朿lear()銆乪vict()涔嬪悗錛屾寔涔呭璞″彉鎴愯劚綆″璞★紝姝ゆ椂鎸佷箙瀵硅薄浼氬彉鎴愯劚綆″璞★紝姝ゆ椂璇ュ璞¤櫧鐒跺叿鏈夋暟鎹簱璇嗗埆鍊鹼紝浣嗗畠宸蹭笉鍦℉Ibernate鎸佷箙灞傜殑綆＄悊涔嬩笅銆?/p>
鎸佷箙瀵硅薄鍏鋒湁濡備笅鐗圭偣錛?/p>
1. 鍜宻ession瀹炰緥鍏寵仈錛?/p>
2. 鍦ㄦ暟鎹簱涓湁涓庝箣鍏寵仈鐨勮褰曘?/p>
- 鑴辯鎬?/strong>
褰撲笌鏌愭寔涔呭璞″叧鑱旂殑session琚叧闂悗錛岃鎸佷箙瀵硅薄杞彉涓鴻劚綆″璞°傚綋鑴辯瀵硅薄琚噸鏂板叧鑱斿埌session涓婃椂錛屽茍鍐嶆杞彉鎴愭寔涔呭璞°?/p>
鑴辯瀵硅薄鎷ユ湁鏁版嵁搴撶殑璇嗗埆鍊鹼紝鍙氳繃update()銆乻aveOrUpdate()絳夋柟娉曪紝杞彉鎴愭寔涔呭璞°?/p>
鑴辯瀵硅薄鍏鋒湁濡備笅鐗圭偣錛?/p>
1. 鏈川涓婁笌鐬椂瀵硅薄鐩稿悓錛屽湪娌℃湁浠諱綍鍙橀噺寮曠敤瀹冩椂錛孞VM浼氬湪閫傚綋鐨勬椂鍊欏皢瀹冨洖鏀訛紱
2. 姣旂灛鏃跺璞″浜嗕竴涓暟鎹簱璁板綍鏍囪瘑鍊箋?/p>