| java浠ｇ爜: |
|
Session session = ...; Transaction tx = ...; Parent parent = (Parent) session.load(Parent.class, id); Child child = new Child(); child.setParent(parent); child.setName("sun"); parent.addChild(child); s.update(parent); s.flush(); tx.commit(); s.close(); |
鍦ㄤ笂渚嬩腑錛岀▼搴忓茍娌℃湁鏄懼紡鐨剆ession.save(child); 閭ｄ箞Hibernate闇瑕佺煡閬揷hild絀剁珶鏄竴涓復(fù)鏃跺璞★紝榪樻槸宸茬粡鍦ㄦ暟鎹簱涓湁鐨勬寔涔呭璞°傚鏋渃hild鏄竴涓柊鍒涘緩鐨勪復(fù)鏃跺璞?鏈緥涓氨鏄繖縐嶆儏鍐?錛岄偅涔圚ibernate搴旇鑷姩浜х敓session.save(child)榪欐牱鐨勬搷浣滐紝濡傛灉child鏄凡緇忓湪鏁版嵁搴撲腑鏈夌殑鎸佷箙瀵硅薄錛岄偅涔圚ibernate搴旇鑷姩浜х敓session.update(child)榪欐牱鐨勬搷浣溿?
鍥犳鎴戜滑闇瑕佹殫紺轟竴涓婬ibernate錛岀┒绔焎hild瀵硅薄搴旇瀵瑰畠鑷姩save榪樻槸update銆傚湪涓婁緥涓紝鏄劇劧鎴戜滑搴旇鏆楃ずHibernate瀵筩hild鑷姩save錛岃屼笉鏄嚜鍔╱pdate銆傞偅涔圚ibernate濡備綍鍒ゆ柇絀剁珶瀵筩hild鏄痵ave榪樻槸update鍛紵瀹冧細(xì)鍙栦竴涓媍hild鐨勪富閿睘鎬?child.getId() 錛岃繖閲屽亣璁緄d鏄?java.lang.Integer綾誨瀷鐨勩傚鏋滃彇鍒扮殑Id鍊煎拰hbm鏄犲皠鏂囦歡涓寚瀹氱殑unsave-value鐩哥瓑錛岄偅涔圚ibernate璁や負(fù)child鏄柊鐨勫唴瀛樹(shù)復(fù)鏃跺璞★紝鍙戦乻ave錛屽鏋滀笉鐩哥瓑錛岄偅涔圚ibernate璁や負(fù)child鏄凡緇忔寔涔呰繃鐨勫璞★紝鍙戦乽pdate銆?
unsaved-value="null" (榛樿鎯呭喌錛岄傜敤浜庡ぇ澶氭暟瀵硅薄綾誨瀷涓婚敭 Integer/Long/String/...)
褰揌ibernate鍙栦竴涓媍hild鐨処d錛屽彇鍑烘潵鐨勬槸null(鍦ㄤ笂渚嬩腑鑲畾鍙栧嚭鏉ョ殑鏄痭ull)錛屽拰unsaved-value璁懼畾鍊肩浉絳夛紝鍙戦乻ave(child)
褰揌ibernate鍙栦竴涓媍hild鐨刬d錛屽彇鍑烘潵鐨勪笉鏄痭ull錛岄偅涔堝拰unsaved-value璁懼畾鍊間笉鐩哥瓑錛屽彂閫乽pdate(child)
渚嬪涓嬮潰鐨勬儏鍐碉細(xì)
| java浠ｇ爜: |
|
Session session = ...; Transaction tx = ...; Parent parent = (Parent) session.load(Parent.class, id); Child child = (Child) session.load(Child.class, childId); child.setParent(parent); child.setName("sun"); parent.addChild(child); s.update(parent); s.flush(); tx.commit(); s.close(); |
child宸茬粡鍦ㄦ暟鎹簱涓湁浜?jiǎn)锛屾槸涓涓寔涔呭寲鐨勫璞★紝涓嶆槸鏂板垱寤虹殑錛屽洜姝ゆ垜浠笇鏈汬ibernate鍙戦乽pdate(child)錛屽湪璇ヤ緥涓紝Hibernate鍙栦竴涓媍hild.getId()錛屽拰unsave-value鎸囧畾鐨刵ull姣斿涓涓嬶紝鍙戠幇涓嶇浉絳夛紝閭ｄ箞鍙戦乽pdate(child)銆?
BTW: parent瀵硅薄涓嶉渶瑕佹搷蹇?jī)锛屽洜湄?fù)紼嬪簭鏄懼紡鐨勫parent鏈塴oad鎿嶄綔鍜寀pdate鐨勬搷浣滐紝涓嶉渶瑕丠ibernate鑷繁鏉ュ垽鏂┒绔熸槸save榪樻槸update浜?jiǎn)銆傛垜浠娉ㄦ剰鐨勫彧鏄痗hild瀵硅薄鐨勬搷浣溿傚彟澶?span style="color: #ffa34f">unsaved-value鏄畾涔夊湪Child綾葷殑涓婚敭灞炴т腑鐨勩?
| java浠ｇ爜: |
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<class name="Child" table="child"> <id column="id" name="id" type="integer" unsaved-value="null"> <generator class="identity"/> </id> ... </class> |
濡傛灉涓婚敭灞炴т笉鏄璞″瀷錛岃屾槸鍩烘湰綾誨瀷錛屽int/long/double/...錛岄偅涔堜綘闇瑕佹寚瀹氫竴涓暟鍊煎瀷鐨?span style="color: #ffa34f">unsaved-value錛屼緥濡傦細(xì)
| java浠ｇ爜: |
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unsaved-null="0" |
鍦ㄦ鎻愰啋澶у錛屽緢澶氫漢浠ヤ負(fù)瀵逛富閿睘鎬у畾涔変負(fù)int/long錛屾瘮瀹氫箟涓篒nteger/Long榪愯鏁堢巼鏉ュ緱楂橈紝璁や負(fù)鍩烘湰綾誨瀷涓嶉渶瑕佽繘琛屽璞＄殑灝佽鍜岃В鏋勬搷浣滐紝鍥犳鍠滄鎶婁富閿畾涔変負(fù)int/long鐨勩備絾瀹為檯涓婏紝Hibernate鍐呴儴鎬繪槸鎶婁富閿漿鎹負(fù)瀵硅薄鍨嬭繘琛屾搷浣滅殑錛屽氨綆椾綘瀹氫箟涓篿nt/long鍨嬬殑錛孒ibernate鍐呴儴涔熻榪涜涓嬈″璞℃瀯閫犳搷浣滐紝榪斿洖緇欎綘鐨勬椂鍊欙紝榪樿榪涜瑙ｆ瀯鎿嶄綔錛屾晥鐜囧彲鑳藉弽鑰屼綆涔熻涓嶅畾銆傚洜姝ゅぇ瀹朵竴瀹氳鎵漿涓涓鐐癸紝鍦℉ibernate涓紝涓婚敭灞炴у畾涔変負(fù)鍩烘湰綾誨瀷錛屽茍涓嶈兘澶熸瘮瀹氫箟涓哄璞″瀷鏁堢巼鏉ョ殑楂橈紝鑰屼笖涔熷浜?jiǎn)寰堝楹荤儲(chǔ)锛屽洜姝ゅ圾櫘ぇ瀹朵娇鐢ㄥ璞″瀷鐨処nteger/Long瀹氫箟涓婚敭銆?
unsaved-value="none"鍜?
unsaved-value="any"
涓諱富瑕佺敤鍦ㄤ富閿睘鎬т笉鏄氳繃Hibernate鐢熸垚錛岃屾槸紼嬪簭鑷繁setId()鐨勬椂鍊欍?
鍦ㄨ繖閲屽璇翠竴鍙ワ紝寮虹儓寤鴻浣跨敤Hibernate鐨刬d generator錛屾垨鑰呬綘鍙互鑷繁鎵╁睍Hibernate鐨刬d generator錛岀壒鍒敞鎰忎笉瑕佷嬌鐢ㄦ湁瀹為檯鍚箟鐨勫瓧孌靛綋鍋氫富閿潵鐢紒渚嬪鐢ㄦ埛綾籙ser錛屽緢澶氫漢鍠滄鐢ㄧ敤鎴風(fēng)櫥闄嗗悕縐板仛涓轟富閿紝榪欐槸涓涓緢涓嶅ソ鐨勪範(fàn)鎯紝褰撶敤鎴風(fēng)被鍜屽叾浠栧疄浣撶被鏈夊叧鑱斿叧緋葷殑鏃跺欙紝涓囦竴浣犻渶瑕佷慨鏀圭敤鎴風(fēng)櫥闄嗗悕縐幫紝涓鏀瑰氨闇瑕佹敼濂藉嚑寮犺〃涓殑鏁版嵁銆傚伓鍚堟уお楂橈紝鑰屽鏋滀綘浣跨敤鏃犱笟鍔℃剰涔夌殑id generator錛岄偅涔堜慨鏀圭敤鎴峰悕縐幫紝灝卞彧淇敼user琛ㄥ氨琛屼簡(jiǎn)銆?
鐢辮繖涓棶棰樺紩鐢沖嚭鏉ワ紝濡傛灉浣犱弗鏍兼寜鐓ц繖涓師鍒欐潵璁捐鏁版嵁搴擄紝閭ｄ箞浣犲熀鏈笂鏄敤涓嶅埌鎵嬪伐鏉etId()鐨勶紝浣犵敤Hibernate鐨刬d generator灝監(jiān)K浜?jiǎn)銆傚洜姝や綘涔熶笉闇瑕佷簡(jiǎn)瑙ｅ綋
unsaved-value="none"鍜?
unsaved-value="any"
絀剁珶鏈変粈涔堝惈涔変簡(jiǎn)銆傚鏋滀綘闈炶鐢╝ssigned涓嶅彲錛岄偅涔堢戶緇В閲婁竴涓嬶細(xì)
unsaved-value="none" 鐨勬椂鍊欙紝鐢變簬涓嶈涓婚敭灞炴т負(fù)浠諱綍鍊鹼紝閮戒笉鍙兘涓簄one錛屽洜姝ibernate鎬繪槸瀵筩hild瀵硅薄鍙戦乽pdate(child)
unsaved-value="any" 鐨勬椂鍊欙紝鐢變簬涓嶈涓婚敭灞炴т負(fù)浠諱綍鍊鹼紝閮借偗瀹氫負(fù)any錛屽洜姝ibernate鎬繪槸瀵筩hild瀵硅薄鍙戦乻ave(child)
澶у鏁版儏鍐典笅錛屼綘鍙互閬垮厤浣跨敤assigned錛屽彧鏈夊綋浣犱嬌鐢ㄥ鍚堜富閿殑鏃跺欎笉寰椾笉鎵嬪伐setId()錛岃繖鏃跺欓渶瑕佷綘鑷繁鑰冭檻絀剁珶鎬庝箞璁劇疆unsaved-value浜?jiǎn)锛屾犚?guī)嵁浣犺嚜宸辯殑闇瑕佹潵瀹氥?
BTW: Gavin King寮虹儓涓嶅緩璁嬌鐢╟omposite-id錛屽己鐑堝緩璁嬌鐢║serType銆?
鍥犳錛屽鏋滀綘鍦ㄧ郴緇熻璁＄殑鏃跺欙紝閬靛驚濡備笅鍘熷垯錛?
1銆佷嬌鐢℉ibernate鐨刬d generator鏉ョ敓鎴愭棤涓氬姟鎰忎箟鐨勪富閿紝涓嶄嬌鐢ㄦ湁涓氬姟鍚箟鐨勫瓧孌靛仛涓婚敭錛屼笉浣跨敤assigned銆?
2銆佷嬌鐢ㄥ璞＄被鍨?String/Integer/Long/...)鏉ュ仛涓婚敭錛岃屼笉浣跨敤鍩虹綾誨瀷(int/long/...)鍋氫富閿?
3銆佷笉浣跨敤composite-id鏉ュ鐞嗗鍚堜富閿殑鎯呭喌錛岃屼嬌鐢║serType鏉ュ鐞嗚縐嶆儏鍐點(diǎn)?/span>
閭ｄ箞浣犳案榪滅敤鐨勬槸unsaved-value="null" 錛屼笉鍙兘鐢ㄥ埌any/none/..浜?jiǎn)銆?/span>
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