{"id":9556,"date":"2014-01-28T23:44:07","date_gmt":"2014-01-28T15:44:07","guid":{"rendered":"https:\/\/lifeparty.idv.tw\/blog\/?p=9556"},"modified":"2014-01-29T07:13:30","modified_gmt":"2014-01-28T23:13:30","slug":"%e6%9f%a5%e8%a9%a2%e7%9a%84%e5%ae%a3%e5%91%8a%e5%bc%8f%e8%aa%9e%e6%84%8f","status":"publish","type":"post","link":"https:\/\/lifeparty.idv.tw\/blog\/archives\/9556","title":{"rendered":"\u67e5\u8a62\u7684\u5ba3\u544a\u5f0f\u8a9e\u610f"},"content":{"rendered":"

\u5beb\u5b8c\u3008\u8a0a\u606f\u62c6\u89e3\u7d44\u5408\u7684\u5ba3\u544a\u5f0f\u8a9e\u610f<\/a>\u3009\uff08\u539f\u7bc7\u540d\uff1a\u7c21\u5316\u8a2d\u8a08\u7684\u5ef6\u9072\u904b\u7b97\uff0d\u5176\u4e00\uff09\u4e4b\u5f8c\uff0c\u5230\u73fe\u5728\u540c\u4eba\u624d\u63a5\u8457\u5beb\u4e0b\u7b2c\u4e8c\u7bc7\u7cfb\u5217\u6587\u7ae0\u3002\u5176\u5be6\u6703\u9694\u90a3\u9ebc\u4e45\u624d\u518d\u52d5\u7b46\u662f\u6709\u539f\u56e0\u7684\uff0c\u672c\u4f86\u7b2c\u4e8c\u7bc7\u6253\u7b97\u8981\u5beb\u5256\u6790\u547d\u4ee4\u5217\u7684\u5ba3\u544a\u5f0f\u8a9e\u610f\uff0c\u4e0d\u904e\u540c\u4eba\u89ba\u5f97\u6211\u539f\u5148\u7684\u8a2d\u8a08\u9084\u4e0d\u5920\u597d\uff0c\u65bc\u662f\u5c31\u66ab\u6642\u5148\u628a\u5b83\u64f1\u7f6e\u4e0b\u4f86\u3002\u7d50\u679c\u4e00\u64f1\u5c31\u64f1\u4e86\u597d\u4e45\uff0c\u6162\u6162\u5730\u4e5f\u8b93\u6211\u89ba\u5f97\u6c92\u6709\u5fc5\u8981\u91cd\u65b0\u5be6\u4f5c\u547d\u4ee4\u5256\u6790\u5217\u7684\u5ba3\u544a\u5f0f\u8a9e\u610f\uff0c\u56e0\u70ba\u7562\u7adf\u6703\u4f7f\u7528\u5230\u7684\u6a5f\u6703\u4e26\u4e0d\u591a\u3002\u5176\u5be6\u547d\u4ee4\u5217\u5256\u6790\u7684\u5ba3\u544a\u5f0f\u8a9e\u610f\u548c\u524d\u4e00\u7bc7\u6587\u7ae0\u7684\u8a2d\u8a08\u539f\u7406\u61c9\u8a72\u662f\u4e00\u81f4\u7684\uff0c\u56e0\u6b64\u540c\u4eba\u5f8c\u4f86\u6c7a\u5b9a\u8981\u8df3\u904e\u5b83\u3002\u525b\u597d\u8fd1\u770b\u5230\u6709\u670b\u53cb\u8a0e\u8ad6\u76f8\u95dc\u7684\u8b70\u984c\uff0c\u6fc0\u767c\u6211\u5b8c\u6210\u7cfb\u5217\u6587\u7ae0\u7684\u52d5\u529b\uff0c\u9019\u4e00\u7bc7\u6240\u8981\u63a2\u8a0e\u7684\u4e3b\u984c\u6b63\u662f\u6709\u95dc\u65bc\u67e5\u8a62\u7684\u5ba3\u544a\u5f0f\u8a9e\u610f\u3002<\/p>\n

\u9019\u7bc7\u6587\u7ae0\u540c\u4eba\u4e0d\u60f3\u8ac7\u592a\u591a\u7684\u7406\u8ad6\uff0c\u8b93\u6211\u5011\u5148\u4f86\u770b\u4e00\u6bb5\u67e5\u8a62\u7684\u5ba3\u544a\u5f0f\u8a9e\u610f\u7684 client code\uff1a<\/p>\n

list<MS1LineItem> t0101s = ctx\r\n\t.from(T010_JOIN_CST_PRD)\r\n\t.where(new T010DateEquals(ctx.getToday()))\r\n\t.where(new T010OperDateTimeBetween(nextTime, interval))\r\n\t.where(new T010PrId2NotEquals(PRID2_0002000))\r\n\t.select(T010_SELECTION, ctx,\u00a0MS1FromT010Selector(\r\n\t\tctx.getToday(), T010ST_1000));\r\n\r\nlist<MS1LineItem> t0102s = ctx\r\n\t.from(T010_JOIN_CST_PRD)\r\n\t.where(new T010DateEquals(ctx.getToday()))\r\n\t.where(new T010OperDateTimeBetween(nextTime, interval))\r\n\t.where(new T010PrId2Equals(PRID2_0002000))\r\n\t.select(T010_SELECTION, ctx, MS1FromT010Selector(\r\n\t\tctx.getToday(), T010ST_2000));\r\n\r\nlist<pair<MS1LineItem, MS1LineItem> > t020s = ctx\r\n\t.from(T020_JOIN_CST_PRD)\r\n\t.where(new T020DateEquals(ctx.getToday()))\r\n\t.where(new T020OperDateTimeBetween(nextTime, interval))\r\n\t.select(T020_SELECTION, ctx, MS1FromT020Selector(\r\n\t\tctx.getToday()));\r\n\r\nlist<MS1LineItem> t040s = ctx\r\n\t.from(T040_JOIN_CST_PRD)\r\n\t.where(new T040DateEquals(ctx.getToday()))\r\n\t.where(new T040OperDateTimeBetween(nextTime, interval))\r\n\t.select(T040_SELECTION, ctx, MS1FromT040Selector(\r\n\t\tctx.getToday()));\r\n\r\nMS1Writer writer(nextTime);\r\n\r\nwriter(t0101s);\r\nwriter(t0102s);\r\nwriter(t020s);\r\nwriter(t040s);\r\nwriter.save();<\/pre>\n
\u4ee5\u4e0a\u662f\u4e00\u500b\u8f49\u6a94\u7a0b\u5f0f\u7684\u4e00\u90e8\u5206\u7247\u65b7\uff0c\u70ba\u4e86\u907f\u514d\u727d\u6d89\u696d\u52d9\u908f\u8f2f\u8cc7\u6599\u7684\u654f\u611f\uff0c\u540c\u4eba\u5df2\u7d93\u7a0d\u5fae\u505a\u4e86\u4e00\u9ede\u4fee\u6539\u3002\u9019\u4e00\u6bb5\u7a0b\u5f0f\u78bc\u63a1\u7528\u5e73\u8216\u76f4\u654d\u7684\u5beb\u6cd5\uff0c\u61c9\u8a72\u5f88\u5bb9\u6613\u53ef\u4ee5\u770b\u51fa\u9019\u6bb5\u7a0b\u5f0f\u78bc\u7684\u610f\u5716\u3002\u5f9e\u9019\u6bb5\u7a0b\u5f0f\u6211\u5011\u770b\u5230 ctx \u4ee3\u8868\u7cfb\u7d71\u904b\u4f5c\u7684\u74b0\u5883\uff0c\u5176\u4e2d\u5b9a\u7fa9\u4e86\u67e5\u8a62\u9700\u8981\u4f7f\u7528\u7684\u53c3\u6578\uff08\u4f8b\u5982\u7cfb\u7d71\u65e5\u671f\uff09\uff0c\u4e26\u4e14\u8ca0\u8cac\u5efa\u7acb\u8cc7\u6599\u5eab\u9023\u7dda\u4ee5\u4f9b\u67e5\u8a62\u4f7f\u7528\u3002<\/p>\n
\u5f9e\u7a0b\u5f0f\u78bc\u7684\u8a9e\u610f\u6211\u5011\u770b\u5230\uff0c\u6bcf\u4e00\u6bb5\u67e5\u8a62\u662f\u85c9\u7531 ctx \u7684 from() \u7522\u751f\u67e5\u8a62\u7684\u5be6\u9ad4\uff0c\u7136\u5f8c\u518d\u7528\u5e7e\u500b where() \u4f86\u6307\u660e\u67e5\u8a62\u689d\u4ef6\uff0c\u6700\u5f8c\u518d\u7528 select() \u628a\u67e5\u8a62\u5230\u7684\u8cc7\u6599\u4ee5 list \u56de\u50b3\u3002\u5176\u5be6\u540c\u4eba\u5728\u4ee5\u524d\u5728\u3008\u6c38\u7e8c\u7269\u4ef6\u67e5\u8a62\u4e4b\u8a2d\u8a08\uff08\u5176\u4e00\uff09<\/a>\u3009\u3001\u3008\u6c38\u7e8c\u7269\u4ef6\u67e5\u8a62\u4e4b\u8a2d\u8a08\uff08\u5176\u4e8c\uff09<\/a>\u3009\u6709\u8ac7\u904e\u985e\u4f3c\u7684\u8868\u9054\u8a9e\u610f\uff0c\u4f46\u9019\u88e1\u548c\u4ee5\u524d\u904b\u7528 Design Pattern \u7684\u624b\u6cd5\u7565\u6709\u4e0d\u540c\uff0c\u5728\u9019\u88e1\u540c\u4eba\u662f\u4ee5 C++ template \u4f86\u5be6\u73fe Functional Programming<\/a> \u7684\u6982\u5ff5\uff0c\u76f8\u4fe1\u6709\u63a5\u89f8\u904e LINQ<\/a> \u7684\u670b\u53cb\uff0c\u5c0d\u9019\u6a23\u7684\u5beb\u6cd5\u61c9\u8a72\u4e0d\u964c\u751f\u3002<\/p>\n
\u547c\u53eb\u7aef\u900f\u904e ctx \u7684 from() \u751f\u6210\u4e00\u500b\u67e5\u8a62\u7684\u5be6\u9ad4\uff0c\u7136\u5f8c\u547c\u53eb\u7aef\u518d\u5229\u7528 where() \u4f86\u6307\u5b9a\u67e5\u8a62\u689d\u4ef6\u3002where() \u6703\u50b3\u56de\u67e5\u8a62\u672c\u8eab\uff0c\u9019\u6a23\u547c\u53eb\u7aef\u53c8\u53ef\u4ee5\u518d\u6b21\u4f7f\u7528 where() \u589e\u6dfb\u66f4\u591a\u7684\u67e5\u8a62\u689d\u4ef6\uff08\u76f8\u7576\u65bc\u4ee5 and \u7684\u95dc\u4fc2\u904b\u7b97\u5f0f\u9023\u7d50\u591a\u500b\u67e5\u8a62\u689d\u4ef6\uff09\u3002\u5be6\u969b\u4e0a\uff0cwhere() \u4e26\u672a\u99ac\u4e0a\u8655\u7406\u6307\u5b9a\u7684\u67e5\u8a62\u689d\u4ef6\uff0c\u800c\u53ea\u662f\u5efa\u7acb\u61c9\u5c0d\u7684\u8868\u793a\u5f0f\u7b49\u5230\u6700\u5f8c\u547c\u53eb select() \u624d\u6703\u771f\u7684\u6839\u64da\u6240\u6709\u5df2\u52a0\u5165\u7684\u67e5\u8a62\u689d\u4ef6\u67e5\u8a62\u8cc7\u6599\u800c\u56de\u50b3\u7d50\u679c\u3002  \u4e00\u500b\u67e5\u8a62\u53ef\u4ee5\u8907\u5408\u591a\u500b\u67e5\u8a62\u689d\u4ef6\uff0c\u5b8c\u6574\u7684\u67e5\u8a62\u689d\u4ef6\u6211\u5011\u7a31\u70ba criteria\uff0c\u7136\u5f8c\u628a\u67e5\u8a62\u7d50\u679c\u8f49\u63db\u6210\u5c0d\u61c9\u7684 domain object \u7684\u96c6\u5408\uff08std::list \u6216 std::map\uff09\u3002\u9019\u6a23\u67e5\u8a62\u5c31\u53ef\u8868\u793a\u70ba Query<T> \u7684 class template\uff0c\u5b83\u7684\u5b9a\u7fa9\u5982\u4e0b\u9762\u9019\u6bb5\u7a0b\u5f0f\u78bc\u6240\u793a\uff1a<\/p>\n
template <typename T, typename R>\r\nclass CriteriaExpression {\r\npublic:\r\n\tvirtual R operator() (const T&) = 0;\r\n};\r\n\r\ntemplate <typename T>\r\nclass Query {\r\nprotected:\r\n\tDbConnection* _dbconn;\r\n\tstring _resource;\r\n\tshared_ptr<CriteriaExpression<T, string> > _criteria;\t\r\n\r\nprivate:\r\n\tQuery<T>& assign(const Query<T>& other) {\r\n\t\t_dbconn = other._dbconn;\r\n\t\t_resource = other._resource;\r\n\t\t_criteria = other._criteria;\r\n\t\treturn *this;\r\n\t}\r\n\r\npublic:\r\n\tQuery(DbConnection* dbconn, const char* resource) :\r\n\t\t_dbconn(dbconn), _resource(resource) {\r\n\t\t_criteria.reset();\r\n\t}\r\n\r\n\tQuery(const Query& other) {\r\n\t\tassign(other);\r\n\t}\r\n\r\n\tvirtual ~Query() {\r\n\t}\r\n\r\n\tQuery<T>& operator= (const Query<T>& other) {\r\n\t\treturn assign(other);\r\n\t}\r\n\r\npublic:\r\n\tQuery<T>& where(CriteriaExpression<T,\r\n\t\tstring>* criteria) {\r\n\t\tshared_ptr<CriteriaExpression<T, string> >\r\n\t\t\tbeforeCriteria = _criteria;\r\n\t\t_criteria = AndOperator<T>() (beforeCriteria,\r\n\t\t\tcriteria);\r\n\t\treturn *this;\r\n\t}\r\n\r\n\tQuery<T>& where(\r\n\t\tshared_ptr<CriteriaExpression<T,\r\n\t\tstring> > criteria) {\r\n\t\tshared_ptr<CriteriaExpression<T, string> >\r\n\t\t\tbeforeCriteria = _criteria;\r\n\t\t_criteria = AndOperator<T>() (beforeCriteria,\r\n\t\t\tcriteria);\r\n\t\treturn *this;\r\n\t}\r\n\r\n\tlist<QueryResultSet> select(const char* columns,\r\n\t\tconst T& param, const char* orderBy = NULL) {\r\n\t\tlist<QueryResultSet> rslist;\r\n\r\n\t\tostringstream sql;\r\n\t\tstring cs = columns;\r\n\t\tsize_t pos = 0, found_pos;\r\n\t\twhile ((found_pos = cs.find("%2C", pos)) !=\r\n\t\t\tstring::npos) {\r\n\t\t\tcs.replace(found_pos, 3, 1, COMMA);\r\n\t\t\tpos ++;\r\n\t\t}\r\n\t\tsql << SELECT << cs << FROM << _resource;\r\n\r\n\t\tif (_criteria) {\r\n\t\t\tstring s = _criteria->operator()(param);\r\n\r\n\t\t\tif (!s.empty()) {\r\n\t\t\t\tsql << WHERE << s;\r\n\t\t\t}\r\n\t\t}\r\n\r\n\t\tif (orderBy != NULL) {\r\n\t\t\tsql << ORDER_BY << orderBy;\r\n\t\t}\r\n\r\n\t\tint fetch = FETCH_START;\r\n\r\n\t\trslist.clear();\r\n\t\tif (_dbconn->query(sql.str().c_str(), rslist)) {\r\n\t\t\tLOG(FileAtLine(__FILE__, __LINE__).c_str(),\r\n\t\t\t\t__PRETTY_FUNCTION__,\r\n\t\t\t\t"query results count = %u", rslist.size());\r\n\t\t}\r\n\t\telse {\r\n\t\t\tLOG(FileAtLine(__FILE__, __LINE__).c_str(),\r\n\t\t\t\t__PRETTY_FUNCTION__, "query fail!");\r\n\t\t}\r\n\r\n\t\treturn rslist;\r\n\t}\r\n\r\n\ttemplate <class ElementSelector>\r\n\tlist<typename ElementSelector::result_type> select(\r\n\t\tconst char* columns, const T& param,\r\n\t\tElementSelector selector, const char* orderBy = NULL) {\r\n\t\tlist<QueryResultSet>\r\n\t\t\trslist = select(columns, param, orderBy);\r\n\t\tlist<typename ElementSelector::result_type> result;\r\n\t\tresult.resize(rslist.size());\r\n\t\ttransform(rslist.begin(), rslist.end(), result.begin(),\r\n\t\t\tselector);\r\n\r\n\t\treturn result;\r\n\t}\r\n\r\n\ttemplate <class ElementSelector>\r\n\tlist<typename ElementSelector::result_type> select(\r\n\t\tconst T& param, ElementSelector selector,\r\n\t\tconst char* orderBy = NULL) {\r\n\t\tlist<QueryResultSet> rslist = select(\r\n\t\t\tALL_COLUMNS_SELECTION, param, orderBy);\r\n\t\tlist<typename ElementSelector::result_type> result;\r\n\t\tresult.resize(rslist.size());\r\n\t\ttransform(rslist.begin(), rslist.end(), result.begin(),\r\n\t\t\tselector);\r\n\r\n\t\treturn result;\r\n\t}\r\n\r\n\ttemplate <class ElementSelector, typename KeySelector>\r\n\tmap<typename KeySelector::result_type,\r\n\t\tlist<typename ElementSelector::result_type> >\r\n\t\tselect(const char* columns, const T& param,\r\n\t\tElementSelector elementSelector,\r\n\t\tKeySelector keySelector,\r\n\t\tconst char* orderBy = NULL) {\r\n\t\tlist<QueryResultSet> rslist = select(\r\n\t\t\tcolumns, param, orderBy);\r\n\t\tmap<typename KeySelector::result_type,\r\n\t\t\tlist<typename ElementSelector::result_type> >\r\n\t\t\tresult;\r\n\r\n\t\tresult.clear();\r\n\t\tlist<QueryResultSet>::iterator rs = rslist.begin();\r\n\t\tfor (; rs != rslist.end(); rs ++) {\r\n\t\t\ttypename KeySelector::result_type\r\n\t\t\t\tkeyvalue = keySelector(*rs);\r\n\t\t\tlist<typename ElementSelector::result_type>\r\n\t\t\t\tvaluelist = result[keyvalue];\r\n\r\n\t\t\ttypename ElementSelector::result_type\r\n\t\t\t\tvalue = elementSelector(*rs);\r\n\t\t\tvaluelist.push_back(value);\r\n\t\t\tresult[keyvalue] = valuelist;\r\n\t\t}\r\n\r\n\t\treturn result;\r\n\t}\r\n\r\n\ttemplate <class ElementSelector, typename KeySelector>\r\n\tmap<typename KeySelector::result_type,\r\n\t\tlist<typename ElementSelector::result_type> >\r\n\t\tselect(const T& param, ElementSelector elementSelector,\r\n\t\tKeySelector keySelector, const char* orderBy = NULL) {\r\n\t\tlist<QueryResultSet> rslist = select(\r\n\t\t\tALL_COLUMNS_SELECTION, param, orderBy);\r\n\t\tmap<typename KeySelector::result_type,\r\n\t\t\tlist<typename ElementSelector::result_type> >\r\n\t\t\tresult;\r\n\r\n\t\tresult.clear();\r\n\t\tlist<QueryResultSet>::iterator rs = rslist.begin();\r\n\t\tfor (; rs != rslist.end(); rs ++) {\r\n\t\t\ttypename KeySelector::result_type\r\n\t\t\t\tkeyvalue = keySelector(*rs);\r\n\t\t\tlist<typename ElementSelector::result_type>\r\n\t\t\t\tvaluelist = result[keyvalue];\r\n\r\n\t\t\ttypename ElementSelector::result_type\r\n\t\t\t\tvalue = elementSelector(*rs);\r\n\t\t\tvaluelist.push_back(value);\r\n\t\t\tresult[keyvalue] = valuelist;\r\n\t\t}\r\n\r\n\t\treturn result;\r\n\t}\r\n};<\/pre>\n
Query<T> \u662f\u53c3\u6578\u5316\u4e86\u7cfb\u7d71\u74b0\u5883\u985e\u5225\u7684\u67e5\u8a62\u6cdb\u578b\uff0c\u5b83\u63d0\u4f9b where() \u4f86\u63a5\u53d7 criteria \u7684\u8868\u793a\u5f0f\uff0c\u5b83\u5fc5\u9808\u662f\u4e00\u500b\u4e00\u5143\u51fd\u6578\uff0c\u63d0\u4f9b T \u7684\u985e\u578b\u4e4b\u53c3\u6578\uff0c\u7d50\u679c\u56de\u50b3 sql \u67e5\u8a62\u689d\u4ef6\u5b57\u4e32\u3001\u4ee5\u53ca select() \u4f86\u63a5\u53d7\u628a\u67e5\u8a62\u7d50\u679c\u8f49\u63db\u6210\u5c0d\u61c9 domain object \u7684\u4e00\u5143\u51fd\u6578\uff0c\u4ee5 db \u67e5\u8a62\u7684 query result set \u70ba\u53c3\u6578\uff0c\u56de\u50b3\u5c0d\u61c9\u7684 domain object\u3002\u6211\u5011\u53ef\u4ee5\u628a\u50b3\u5165 where() \u7684\u8868\u793a\u5f0f\u770b\u6210 filter\uff0c\u4ee3\u8868\u904e\u6ffe\u5668\uff0c\u628a\u50b3\u5165 select() \u7684\u8868\u793a\u5f0f\u770b\u6210 projection\uff0c\u4ee3\u8868\u6620\u5c04\u5668\u3002Query<T> \u4e26\u4e0d\u6703\u99ac\u4e0a\u904b\u7b97\u50b3\u5165\u7684\u8868\u793a\u5f0f\uff0c\u76f4\u5230\u547c\u53eb select() \u4e4b\u5f8c\u624d\u6703\u4e00\u6b21\u904b\u7b97\u6240\u6709\u7684\u904e\u6ffe\u5668\u548c\u6620\u5c04\u5668\uff0c\u4e0b\u9762\u9019\u6bb5\u7a0b\u5f0f\u662f\u904e\u6ffe\u5668\u548c\u6620\u5c04\u5668\u7684\u5be6\u4f5c\u7bc4\u4f8b\uff1a<\/p>\n
class MS1FromT010Selector :\r\n\tpublic unary_function<QueryResultSet, MS1LineItem> {\r\nprivate:\r\n\tstring _sctToday;\r\n\tT010SelectionType _selectionType;\r\n\r\npublic:\r\n\tMS1FromT010Selector(const string& sctToday,\r\n\t\tT010SelectionType selectionType) :\r\n\t\t_sctToday(sctToday), _selectionType(selectionType) {}\r\n\t~MS1FromT010Selector() {}\r\n\r\n\tMS1LineItem operator() (QueryResultSet& rs) {\r\n\t\tMS1LineItem ms1;\r\n\t\tms1.seqno = SeqnoGeneration(_sctToday,\r\n\t\t\tMYSYSMS1).getSeqno();\r\n\t\tms1.operation = ((_selectionType == T010ST_1000) ?\r\n\t\t\t'1' : '2');\r\n\t\tms1.prNo1 = rs.getString(T010_MEMBER_ID1, 0, 4);\r\n\t\tms1.accNo1 = rs.getString(T010_CST_ACNO1);\r\n\t\tms1.accCode1 = rs.getChar(T010_CST_KIND1);\r\n\r\n\t\t\/\/ ...\r\n\r\n\t\treturn ms1;\r\n\t}\r\n};\r\n\r\nclass T010DateEquals :\r\n\tpublic CriteriaExpression<MySysContext, string> {\r\nprivate:\r\n\tComparsion<MySysContext, Eq> _comparsion;\r\n\r\npublic:\r\n\tT010DateEquals(const string& dt) : _comparsion(\r\n\t\tnew Column<MySysContext>(T010_DATE),\r\n\t\tnew Constant<MySysContext, string>(dt)) {}\r\n\t~T010DateEquals() {}\r\n\r\n\tstring operator() (const MySysContext& ctx) {\r\n        \treturn _comparsion(ctx);\r\n\t}\r\n};<\/pre>\n
\u5f9e\u4e0a\u9762\u7684\u5be6\u4f5c\u6211\u5011\u53ef\u4ee5\u770b\u5230\u61c9\u7528 C++ template \u5982\u4f55\u5be6\u73fe\u6cdb\u51fd\u7de8\u7a0b\u7684\u6982\u5ff5\uff0c\u5728\u9019\u88e1\u540c\u4eba\u4e26\u6c92\u6709\u63a1\u7528 C++0X<\/a> \u589e\u52a0\u7684 lambda expression\uff0c\u800c\u662f\u904b\u7528 C++ \u7de8\u7a0b\u7684\u4eff\u51fd\u5f0f<\/a> functor \u4f86\u9054\u5230\u5230\u5ef6\u9072\u904b\u7b97\u7684\u76ee\u7684\u3002\u9019\u6a23\u6211\u5011\u5c31\u53ef\u4ee5\u5f88\u8f15\u6613\u5730\u628a\u67e5\u8a62\u689d\u4ef6\u548c\u8cc7\u6599\u8f49\u63db\u7684\u90e8\u5206\u62bd\u96e2\u51fa\u4f86\uff1b\u904e\u53bb\u5728\u547d\u4ee4\u5f0f\u7684\u7a0b\u5f0f\u8a9e\u610f\u4e0b\uff0c\u5f88\u591a\u6642\u5019\uff0c\u6211\u5011\u5e38\u56e0\u70ba\u8981\u601d\u8003\u5982\u4f55\u5be6\u4f5c\u67e5\u8a62\u689d\u4ef6\u548c\u8cc7\u6599\u6b04\u4f4d\u7684\u8f49\u63db\u800c\u4f7f\u7a0b\u5f0f\u78bc\u8b8a\u5f97\u5f88\u96dc\u4e82\u3002\u73fe\u5728\u4ee5\u6cdb\u51fd\u7de8\u7a0b\u89c0\u5ff5\u7684\u5ba3\u544a\u5f0f\u8a9e\u610f\u5247\u662f\u85c9\u8457\u7d44\u5408\u591a\u500b\u7c21\u55ae\u7684\u5c0f\u51fd\u5f0f\uff0c\u904b\u7528\u5ef6\u9072\u904b\u7b97\u7684\u6982\u5ff5\u8b93\u7a0b\u5f0f\u78bc\u8b8a\u5f97\u66f4\u7c21\u6f54\u3001\u800c\u4e14\u66f4\u8b93\u4eba\u4e00\u76ee\u4e86\u7136\u77e5\u9053\u7a0b\u5f0f\u7684\u610f\u5716\uff1b\u8b93\u4eba\u5011\u53ea\u8981\u5c08\u6ce8\u65bc\u7cfb\u7d71\u5728\u505a\u4ec0\u9ebc\u4e8b\u800c\u4e0d\u662f\u727d\u626f\u7e41\u8907\u7684\u5be6\u4f5c\u7d30\u7bc0\u7684\u63cf\u8ff0\uff0c\u4f7f\u7a0b\u5f0f\u8b8a\u7684\u66f4\u6709\u5f48\u6027\u4e14\u7c21\u660e\u6613\u8b80\u3002<\/p>\n
\u4e0d\u904e\u9650\u65bc\u7bc7\u8f3b\uff0c\u540c\u4eba\u6c92\u6709\u8fa6\u6cd5\u4ea4\u5f85\u5be6\u4f5c CriteriaExpression<T, string> \u7684\u5404\u7a2e\u8868\u793a\u5f0f\uff0c\u5b83\u5011\u5305\u62ec\u5404\u7a2e\u6bd4\u8f03\u904b\u7b97\u5b50\u3001\u95dc\u4fc2\u904b\u7b97\u5b50\u3001\u5404\u7a2e\u985e\u578b\u7684\u5e38\u6578\u3001\u53c3\u6578\u7b49\u8868\u793a\u5f0f\uff0c\u5b9a\u7fa9\u5b83\u5011\u4e26\u4e0d\u56f0\u96e3\uff0c\u4f46\u8981\u7528\u6bd4\u8f03\u7cbe\u7c21\u7684\u8868\u793a\u65b9\u5f0f\u4f86\u8868\u793a\u6574\u500b\u8a9e\u6cd5\u6a39\uff0c\u4e5f\u8b93\u540c\u4eba\u82b1\u4e86\u4e0d\u5c11\u5de5\u592b\u3002\u5176\u5be6\u9019\u4e9b\u8868\u793a\u5f0f\uff0c\u6211\u4e26\u4e0d\u662f\u4e00\u958b\u59cb\u5c31\u7aae\u8209\u6240\u6709\u8868\u793a\u5f0f\uff0c\u800c\u662f\u7528\u5230\u7684\u6642\u5019\u624d\u52a0\u5165\uff0c\u7136\u5f8c\u518d\u6162\u6162\u8abf\u6574\u6539\u5584\uff0c\u8b93\u6574\u500b\u67e5\u8a62\u7684\u5ba3\u544a\u8a9e\u610f\u8b8a\u5f97\u66f4\u7c21\u55ae\u4e00\u9ede\u3002\u9019\u904e\u7a0b\u8b93\u540c\u4eba\u9ad4\u6703\u6cdb\u51fd\u7de8\u7a0b\u548c\u7269\u4ef6\u5c0e\u5411\u5178\u7bc4\u7684\u642d\u914d\uff0c\u5176\u6a02\u8da3\u662f\u7121\u7aae\u7684\u5440\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
\u672c\u4f86\u7b2c\u4e8c\u7bc7\u6253\u7b97\u8981\u5beb\u5256\u6790\u547d\u4ee4\u5217\u7684\u5ba3\u544a\u5f0f\u8a9e\u610f\uff0c\u4e0d\u904e\u540c\u4eba\u89ba\u5f97\u6211\u539f\u5148\u7684\u8a2d\u8a08\u9084\u4e0d\u5920\u597d\uff0c\u65bc\u662f\u5c31\u66ab\u6642\u5148\u628a\u5b83\u64f1\u7f6e\u4e0b\u4f86\u3002\u7d50\u679c\u4e00\u64f1\u5c31\u64f1\u4e86\u597d\u4e45\uff0c\u6162\u6162\u5730\u4e5f\u8b93\u6211\u89ba\u5f97\u6c92\u6709\u5fc5\u8981\u91cd\u65b0\u5be6\u4f5c\u547d\u4ee4\u5256\u6790\u5217\u7684\u5ba3\u544a\u5f0f\u8a9e\u610f\uff0c\u56e0\u70ba\u7562\u7adf\u6703\u4f7f\u7528\u5230\u7684\u6a5f\u6703\u4e26\u4e0d\u591a\u3002\u5176\u5be6\u547d\u4ee4\u5217\u5256\u6790\u7684\u5ba3\u544a\u5f0f\u8a9e\u610f\u548c\u524d\u4e00\u7bc7\u6587\u7ae0\u7684\u8a2d\u8a08\u539f\u7406\u61c9\u8a72\u662f\u4e00\u81f4\u7684\uff0c\u56e0\u6b64\u540c\u4eba\u5f8c\u4f86\u6c7a\u5b9a\u8981\u8df3\u904e\u5b83\u3002\u525b\u597d\u8fd1\u770b\u5230\u6709\u670b\u53cb\u8a0e\u8ad6\u76f8\u95dc\u7684\u8b70\u984c\uff0c\u6fc0\u767c\u6211\u5b8c\u6210\u7cfb\u5217\u6587\u7ae0\u7684\u52d5\u529b\uff0c\u9019\u4e00\u7bc7\u6240\u8981\u63a2\u8a0e\u7684\u4e3b\u984c\u6b63\u662f\u6709\u95dc\u65bc\u67e5\u8a62\u7684\u5ba3\u544a\u5f0f\u8a9e\u610f\u3002 \u95b1\u8b80\u5168\u6587 →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[29,49,37,43,19],"tags":[],"class_list":["post-9556","post","type-post","status-publish","format-standard","hentry","category-29","category-49","category-37","category-43","category-19"],"_links":{"self":[{"href":"https:\/\/lifeparty.idv.tw\/blog\/wp-json\/wp\/v2\/posts\/9556","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lifeparty.idv.tw\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lifeparty.idv.tw\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lifeparty.idv.tw\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/lifeparty.idv.tw\/blog\/wp-json\/wp\/v2\/comments?post=9556"}],"version-history":[{"count":138,"href":"https:\/\/lifeparty.idv.tw\/blog\/wp-json\/wp\/v2\/posts\/9556\/revisions"}],"predecessor-version":[{"id":9696,"href":"https:\/\/lifeparty.idv.tw\/blog\/wp-json\/wp\/v2\/posts\/9556\/revisions\/9696"}],"wp:attachment":[{"href":"https:\/\/lifeparty.idv.tw\/blog\/wp-json\/wp\/v2\/media?parent=9556"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lifeparty.idv.tw\/blog\/wp-json\/wp\/v2\/categories?post=9556"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lifeparty.idv.tw\/blog\/wp-json\/wp\/v2\/tags?post=9556"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}