{"id":201320,"date":"2020-11-24T23:42:26","date_gmt":"2020-11-24T15:42:26","guid":{"rendered":"http:\/\/4563.org\/?p=201320"},"modified":"2020-11-24T23:42:26","modified_gmt":"2020-11-24T15:42:26","slug":"%e8%80%81%e5%93%a5%e4%bb%ac%ef%bc%8c%e6%88%91%e6%84%9f%e8%a7%89%e6%88%91%e5%86%99%e7%9a%84%e4%bb%a3%e7%a0%81%e5%83%8f-shi-%e4%b8%80%e6%a0%b7%e3%80%82%e3%80%82%e6%b1%82%e6%8c%87%e7%82%b9","status":"publish","type":"post","link":"http:\/\/4563.org\/?p=201320","title":{"rendered":"\u8001\u54e5\u4eec\uff0c\u6211\u611f\u89c9\u6211\u5199\u7684\u4ee3\u7801\u50cf shi \u4e00\u6837\u3002\u3002\u6c42\u6307\u70b9"},"content":{"rendered":"
\n
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\u8001\u54e5\u4eec\uff0c\u6211\u611f\u89c9\u6211\u5199\u7684\u4ee3\u7801\u50cf shi \u4e00\u6837\u3002\u3002\u6c42\u6307\u70b9 <\/h1>\n

<\/p>\n

\n
\u8cc7\u6df1\u5927\u4f6c : beichenhpy <\/span> <\/i> 6<\/span> <\/div>\n
<\/div>\n<\/p><\/div>\n<\/p><\/div>\n<\/p><\/div>\n
<\/p>\n

\u6545\u4e8b\u662f\u8fd9\u6837\u5b50\u7684\u3002\u3002\u3002<\/h1>\n

<\/p>\n

\u9886\u5bfc\u8ba9\u6211\u5236\u5b9a\u4e2a\u4ee3\u7801\u89c4\u8303\uff08\u5c0f\u90e8\u95e8\u521a\u6210\u7acb\uff09\uff0c\u7136\u540e\u770b\u4e86\u963f\u91cc\u7684\u89c4\u7ea6\uff0c\u770b\u5230\u4ed6\u4eec\u4e0d\u63a8\u8350\u4f7f\u7528\u4e09\u4e2a left join \u4ee5\u4e0a\uff0c\u5fc3\u8840\u6765\u6f6e\u60f3\u6d4b\u4e00\u4e0b left join \u548c\u5728 java \u4e2d\u62fc\u54ea\u4e2a\u5feb\u3002<\/h3>\n

\u7531\u4e8e\u5b9e\u529b\u4e0d\u884c\uff0c\u6a21\u62df\u4e86 200000 \u6761\u6570\u636e\uff0c\u5f53\u4e00\u6b21\u5de6\u8fde\u63a5\u5e76\u4e14\u52a0\u4e0a\u7d22\u5f15\u65f6\uff0c\u5f88\u5feb\u554a\uff0c\u6240\u6709\u6570\u636e\u5927\u6982 200ms\uff0c\u7136\u540e\u6211\u7528 java \u62fc\u63a5\uff0c\u7b97\u4e86\u597d\u4e45\u4e5f\u6ca1\u51fa\u7ed3\u679c\u3002\u3002\u73b0\u5728\u6211\u6000\u7591\u662f\u6211\u5199\u7684\u4e24\u4e2a for \u590d\u6742\u5ea6\u592a\u9ad8\u4e86\uff0c\u8bf7\u5927\u4f6c\u4eec\u5e2e\u5fd9\u770b\u4e00\u4e0b\u6211\u7684 shi \u4e00\u6837\u7684\u4ee3\u7801\u3002\u3002<\/h3>\n
\/\/service \u5c42\u62fc public Page<PersonInfoDTO> getPersonByJava() {         long startTime = System.currentTimeMillis();         IPage<PersonDO> personPage = personMapper.selectPage(new Page<>(),null);         IPage<AddressDO> addressPage = addressMapper.selectPage(new Page<>(),null);         \/\/todo \u83b7\u53d6 person \u4fe1\u606f         List<PersonDO> personDOList = personPage.getRecords();         List<PersonInfoDTO> personInfoDTOList = new ArrayList<>();        \/\/todo \u83b7\u53d6\u6240\u6709 address \u4fe1\u606f         List<AddressDO> addressDOList = addressPage.getRecords();         int personSize = personDOList.size();         int addressSize = addressDOList.size();         for (int i = 0; i < personSize ; i++) {             PersonDO personDO = personDOList.get(i);             PersonInfoDTO personInfoDTO = new PersonInfoDTO();             personInfoDTO.setName(personDO.getName());             personInfoDTO.setSex(personDO.getSex());             personInfoDTO.setId(personDO.getId());             for (int j = 0; j < addressSize; j++) {                 AddressDO addressDO = addressDOList.get(j);                 if (addressDO.getName().equals(personInfoDTO.getName())){                     personInfoDTO.setAddress(addressDO.getAddress());                     personInfoDTOList.add(personInfoDTO);                 }             }         }         Page<PersonInfoDTO> personInfoDTOPage = new Page<>();         personInfoDTOPage.setRecords(personInfoDTOList);         long endTime = System.currentTimeMillis();         long usedTime  = endTime - startTime;         System.out.println(usedTime);         return personInfoDTOPage;     } <\/code><\/pre>\n
 <!--name \u52a0\u4e86\u7d22\u5f15-->  <select id=\"getPersonByJoin\" resultType=\"com.hpy.convertfoodemo.convert.entity.DTO.PersonInfoDTO\">         select t1.id,                t1.name,                t1.sex,                t2.address         from test.person t1         left join test.address t2 on t1.name = t2.name  <\/select> <\/code><\/pre>\n<\/p><\/div>\n
 \u5927\u4f6c\u6709\u8a71\u8aaa<\/b> (14<\/span>)        <\/div>\n
 <\/div>\n<\/p><\/div>\n<\/p><\/div>\n
    \n
  • \n
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     \u8cc7\u6df1\u5927\u4f6c : taogen <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 1. \u4ee3\u7801\u6709\u4e2a\u9519\u8bef\uff0cpersonInfoDTOList.add(personInfoDTO); \u628a\u8fd9\u884c\u653e\u5230\u7b2c\u4e00\u5c42 for \u5faa\u73af\u6700\u540e\u4e00\u884c\u800c\u4e0d\u662f\u7b2c\u4e8c\u5c42 for \u5faa\u73af\u3002\u4fee\u6539\u540e\u518d\u8bd5\u8bd5\u65f6\u95f4\u5427\u3002
    2. \u6570\u636e\u5e93 join \u4e5f\u548c\u4e24\u5c42 for \u5faa\u73af\u7c7b\u4f3c\uff0c\u6570\u636e\u5e93\u53ef\u4ee5\u6709\u7d22\u5f15\uff08\u7d22\u5f15\u6548\u7387 n^2 => nlogn \uff09\uff0cJava \u4e5f\u53ef\u4ee5\u6784\u5efa\u7c7b\u4f3c\u7d22\u5f15\uff0c\u5982 hashmap \u3002
    3. \u5efa\u8bae Java \u4e2d\u6784\u5efa\u7d22\u5f15\uff08\u628a\u7b2c\u4e8c\u5c42 for \u5faa\u73af\u7528 addressMap.get(person.getAddress()) \u66ff\u4ee3\uff0c\u518d\u8bd5\u8bd5\u65f6\u95f4\u6548\u7387\u3002                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
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     \u8cc7\u6df1\u5927\u4f6c : taogen <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 \u4ee3\u7801\u9519\u8bef 2\uff1a
    if (addressDO.getName().equals(personInfoDTO.getName()))
    to
    if (addressDO.getName().equals(personInfoDTO.getAddress()))                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
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     \u8cc7\u6df1\u5927\u4f6c : taogen <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 \u53e6\u5916\uff0c\u6d4b\u8bd5 SQL \u6267\u884c\u65f6\u95f4\u3002SQL \u5e94\u8be5\u76f4\u63a5\u5728\u6570\u636e\u5e93\u4e2d\u6267\u884c\uff0c\u4e0d\u8981\u7528 JDBC \u3002                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
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     \u8cc7\u6df1\u5927\u4f6c : xuanbg <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 \u6240\u8c13\u5c4e\u5473\u4ee3\u7801\uff0c\u5f52\u7eb3\u4e0b\u6765\u5c31\u662f\u8fd9\u51e0\u79cd\u60c5\u51b5\uff1a
    1 \u3001\u591a\u4f59\uff0c\u7ed5\u6765\u7ed5\u53bb\u4e0d\u77e5\u6240\u4e91\u7684\u65e0\u6548\u4ee3\u7801\u3002\u89e3\u51b3\u529e\u6cd5\uff1a\u7406\u6e05\u4e1a\u52a1\u903b\u8f91\uff0c\u5e72\u6389\u91cd\u5199\u3002
    2 \u3001\u903b\u8f91\u4e0d\u5b8c\u5907\uff0c\u4e00\u65e6\u51fa\u73b0\u7279\u6b8a\u60c5\u51b5\u5c31\u4f1a\u51fa bug \u3002\u89e3\u51b3\u529e\u6cd5\uff1a\u591a\u5206\u6790\uff0c\u7136\u540e\u8fdb\u884c\u5f52\u7eb3\uff0c\u4f7f\u5f52\u7eb3\u540e\u7684\u903b\u8f91\u80fd\u8986\u76d6\u6240\u6709\u7684\u53ef\u80fd\u6027\u3002
    3 \u3001\u4f4e\u6548\uff0c\u4f7f\u7528\u4e86\u4e0d\u5408\u9002\u7684\u65b9\u6cd5\u5904\u7406\u6570\u636e\u3002\u89e3\u51b3\u529e\u6cd5\uff1a\u4e0d\u8981\u56e0\u5faa\u5b88\u65e7\uff0c\u4e5f\u4e0d\u8981\u4eba\u4e91\u4ea6\u4e91\u3002\u6269\u5c55\u89c6\u91ce\uff0c\u591a\u5c1d\u8bd5\u65b0\u6280\u672f\u65b0\u601d\u8def\u65b0\u65b9\u6cd5\u3002                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
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     \u8cc7\u6df1\u5927\u4f6c : jzphx <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 \u6709\u65f6\u5019\u89c9\u5f97\u81ea\u5df1\u5199\u51fa\u4e86\u5b8c\u7f8e\u7684\u4e1a\u52a1\u4ee3\u7801\uff0c\u591a\u4e00\u4e2a\u5b57\u7b26\u90fd\u7834\u574f\u7f8e\u611f\uff0c\u5728\u4ea7\u54c1\u5200\u67b6\u8116\u5b50\u7684\u60c5\u51b5\u4e0b\u4e0d\u5f97\u4e0d if else                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
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     \u8cc7\u6df1\u5927\u4f6c : hbolive <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 @jzphx \u8fd9\u79cd\u60c5\u51b5\u5f88\u5e38\u89c1                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
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     \u8cc7\u6df1\u5927\u4f6c : HolmLoh <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 @jzphx #5 
    \u7ecf\u5e38\u78b0\u5230\u8fd9\u79cd\u60c5\u51b5…\u6211\u7684\u505a\u6cd5\u662f\u5982\u679c\u540e\u7eed\u4f1a\u62d3\u5c55\u5f88\u591a\u5206\u652f\u6211\u5c31\u4f1a\u5f00\u59cb\u7ffb\u8bbe\u8ba1\u6a21\u5f0f                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
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     \u8cc7\u6df1\u5927\u4f6c : noparking188 <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 \u6211\u6bcf\u5929\u5de5\u4f5c\u90fd\u7cca                                                             <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
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     \u8cc7\u6df1\u5927\u4f6c : AEDaydreamer <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 @noparking188 \u592a\u7cbe\u8f9f\u4e86,\u7b2c\u4e8c\u5929 review \u4e00\u4e0b\u4ee3\u7801\u53d1\u73b0\u80fd\u4f18\u5316\u7684\u5730\u65b9\u5f88\u591a.\u53ef\u662f\u65b0\u7684\u9700\u6c42\u53c8\u6765\u4e86,\u771f\u7684\u6ca1\u65f6\u95f4\u6539.                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
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     \u8cc7\u6df1\u5927\u4f6c : fangcan <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 \u4f60\u4eec\u91cd\u6784\u5b8c\u4e0d\u9700\u8981\u6d4b\u8bd5\u90e8\u518d\u6d4b\u4e0b\u4e48\uff1f\u8fd8\u662f\u90fd\u662f\u81ea\u5df1\u6d4b\u8bd5\u5417                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
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     \u4e3b<\/span> \u8cc7\u6df1\u5927\u4f6c : beichenhpy <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 @taogen \u611f\u8c22                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
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     \u8cc7\u6df1\u5927\u4f6c : darklowly <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 1 \u597d\u597d\u5199\u6ce8\u91ca\uff0c\u6ce8\u91ca\u7684\u683c\u5f0f\u662f \/\/ \u540e\u9700\u8981\u7a7a\u683c<\/p>\n
    2 \u597d\u597d\u6392\u7248\uff0c\u628a\u4ee3\u7801\u5206\u6210\u903b\u8f91\u4e0a\u7684\u6bb5<\/p>\n
    3 \u597d\u597d\u53d6\u540d\u5b57 getPersonByJava\uff0c\u8fd9\u4e2a\u540d\u5b57\u770b\u8d77\u6765\u662f\u5355\u6570\uff0c\u6b63\u5e38\u60c5\u51b5\u4e0b\u5e94\u8be5\u662f listUsers<\/p>\n
    4 \u4e0d\u719f\u6089 java \u4e0d\u77e5\u9053 personMapper.selectPage \u662f\u5e72\u561b\u7684\uff0c\u9009\u62e9\u67d0\u4e00\u9875\uff1f<\/p>\n
    5 \u5206\u89e3\u4e3a\u4e24\u4e2a\u51fd\u6570\uff0c\u53ef\u80fd\u66f4\u5feb\uff0c\u4f2a\u4ee3\u7801<\/p>\n
    UserDTO getUserByID(string id) {
     user = getUserRecord(id)
     addr = getAddrRecord(id)
     return buildUserDTO(user, addr)
    }<\/p>\n
    Page<UserDTO> listUsers() {
     \/\/ \u5206\u9875\u67e5\u8be2\u7528\u6237 ID\uff0c\u5177\u4f53\u7684\u770b\u4f60\u6846\u67b6\u7684\u8bed\u6cd5
     ids = queryUserIDs()<\/p>\n
     usersDTO = new ArrayListXXXXXXXXXXXX()
     for (id := range ids) {
     user = getUserByID(id)
     usersDTO.add(user)
     } <\/p>\n
     usersDTO 
    }                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
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     \u8cc7\u6df1\u5927\u4f6c : darklowly <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 1 \u597d\u597d\u5199\u6ce8\u91ca\uff0c\u6ce8\u91ca\u7684\u683c\u5f0f\u662f \/\/ \u540e\u9700\u8981\u7a7a\u683c<\/p>\n
    2 \u597d\u597d\u6392\u7248\uff0c\u628a\u4ee3\u7801\u5206\u6210\u903b\u8f91\u4e0a\u7684\u6bb5<\/p>\n
    3 \u597d\u597d\u53d6\u540d\u5b57 getPersonByJava\uff0c\u8fd9\u4e2a\u540d\u5b57\u770b\u8d77\u6765\u662f\u5355\u6570\uff0c\u6b63\u5e38\u60c5\u51b5\u4e0b\u5e94\u8be5\u662f listUsers<\/p>\n
    4 \u4e0d\u719f\u6089 java \u4e0d\u77e5\u9053 personMapper.selectPage \u662f\u5e72\u561b\u7684\uff0c\u9009\u62e9\u67d0\u4e00\u9875\uff1f<\/p>\n
    5 \u5206\u89e3\u4e3a\u4e24\u4e2a\u51fd\u6570\uff0c\u53ef\u80fd\u66f4\u5feb\uff0c\u4f2a\u4ee3\u7801<\/p>\n
    “`
    UserDTO getUserByID(string id) {
     user = getUserRecord(id)
     addr = getAddrRecord(id)
     return buildUserDTO(user, addr)
    }<\/p>\n
    Page<UserDTO> listUsers() {
     \/\/ \u5206\u9875\u67e5\u8be2\u7528\u6237 ID\uff0c\u5177\u4f53\u7684\u770b\u4f60\u6846\u67b6\u7684\u8bed\u6cd5
     ids = queryUserIDs()<\/p>\n
     usersDTO = new ArrayListXXXXXXXXXXXX()
     for (id := range ids) {
     user = getUserByID(id)
     usersDTO.add(user)
     } <\/p>\n
     usersDTO 
    }
    “`                                                            <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
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     \u8cc7\u6df1\u5927\u4f6c : darklowly <\/span>  <\/div>\n
     <\/i>            <\/span> <\/div>\n<\/p><\/div>\n
                                                                 \u4e0d\u77e5\u9053\u600e\u4e48\u652f\u6301 markdown,\u5c06\u5c31\u770b\u5427\u3002<\/p>\n
    \u8fd8\u6709\u4e00\u70b9\uff0c\u4f60\u7684\u4ee3\u7801\u4e5f\u662f\u5bc6\u5bc6\u9ebb\u9ebb\u7684\uff0c\u4e0d\u597d\u770b\u3002\u51fd\u6570\u5185\u90e8\uff0c\u4e0d\u540c\u7684\u903b\u8f91\u533a\uff0c\u9700\u8981\u5206\u6bb5\uff0c\u6bb5\u4e4b\u95f4\u7528\u4e00\u4e2a\u7a7a\u884c\u9694\u5f00\u3002                                                            <\/p><\/div>\n<\/p><\/div>\n<\/li>\n
  • \n","protected":false},"excerpt":{"rendered":"
    \u8001\u54e5\u4eec\uff0c\u6211\u611f\u89c9\u6211\u5199\u7684\u4ee3\u7801\u50cf shi…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[],"tags":[],"_links":{"self":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts\/201320"}],"collection":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=201320"}],"version-history":[{"count":0,"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts\/201320\/revisions"}],"wp:attachment":[{"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=201320"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=201320"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=201320"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}