C++ STL学习资源:Eff_STL.pdf中文版解析

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"Eff_STL.pdf中文版,C++标准模板库" 这篇资源是关于C++标准模板库(STL)的学习资料,名为"Eff_STL.pdf"的中文版,适合那些想要深入理解和应用STL的C++程序员。作者在前言中提到,STL是一个强大的工具,但在早期,由于库的实现差异、编译器对模板支持的不一致以及晦涩的错误信息,使得STL的使用充满了挑战。尽管如此,随着时间的发展,STL逐渐得到了更多的接纳和应用,即使在面对这些问题时,许多专业程序员仍然选择使用STL,因为它提供的高效和可扩展性设计远超传统方法。 STL的核心组成部分包括容器(如vector、list、set等)、迭代器、算法和函数对象。这些组件共同协作,为C++程序员提供了高效的数据管理和操作手段。容器存储元素,迭代器则作为访问和操作这些元素的接口,算法则提供了一组通用的操作,如排序、查找、变换等,而函数对象(functors)则封装了可调用的对象,增强了算法的灵活性。 作者指出,学习STL的一个难点在于缺乏高质量的教育资源和文档。当时的编译器诊断信息往往难以理解,这给开发者带来了困扰。然而,随着C++标准的逐步完善,库和编译器的兼容性增强,以及更优质的文档的出现,STL的使用体验得到了显著提升。现在,程序员可以通过各种在线资源、书籍和社区论坛获取关于STL的详尽知识。 在《Effective STL》这样的书籍中,作者通常会分享一些最佳实践和陷阱,帮助读者避免常见的错误,提高代码质量和性能。例如,理解STL容器的内部工作原理,何时使用迭代器的增量操作而不是索引,以及如何有效地使用算法,都是STL学习的重要部分。此外,了解STL的模板元编程基础也是必不可少的,因为这是STL能够实现高度泛型编程的关键。 C++ STL是一个强大且灵活的库,虽然早期使用时可能存在一些挑战,但随着技术的发展和社区的支持,STL已经成为C++开发者的必备工具之一。通过深入学习和实践,开发者可以充分利用STL的优势,编写出高效、简洁且易于维护的代码。这份Eff_STL.pdf中文版的学习资料正是为了帮助程序员克服这些挑战,更好地掌握STL的精髓。

SELECT PIS.SHOW_FLT_DETAIL AS SHOW_FLT_DETAIL -- new , PIS.SHOW_AWB_DETAIL AS SHOW_AWB_DETAIL -- new , PIS.DISPLAY_AIRLINE_CODE AS CARRIER_CODE , DECODE(PIS.REVERT_FLOW,'N',PIS.FLOW_TYPE,DECODE(PIS.FLOW_TYPE,'I','E','I')) AS FLOW_TYPE , PIS.SHIP_TO_LOCATION AS SHIP_TO_LOCATION , PIS.INVOICE_SEQUENCE AS INVOICE_SEQUENCE , PFT.FLIGHT_DATE AS FLIGHT_DATE , PFT.FLIGHT_CARRIER_CODE AS FLIGHT_CARRIER_CODE , PFT.FLIGHT_SERIAL_NUMBER AS FLIGHT_SERIAL_NUMBER , PFT.FLOW_TYPE AS AIRCRAFT_FLOW , FAST.AIRCRAFT_SERVICE_TYPE AS AIRCRAFT_SERVICE_TYPE , PPT.AWB_NUMBER AS AWB_NUMBER , PPT.WEIGHT AS WEIGHT , PPT.CARGO_HANDLING_OPERATOR AS CARGO_HANDLING_OPERATOR , PPT.SHIPMENT_PACKING_TYPE AS SHIPMENT_PACKING_TYPE , PPT.SHIPMENT_FLOW_TYPE AS SHIPMENT_FLOW_TYPE , PPT.SHIPMENT_BUILD_TYPE AS SHIPMENT_BUILD_TYPE , PPT.SHIPMENT_CARGO_TYPE AS SHIPMENT_CARGO_TYPE , PPT.REVENUE_TYPE AS REVENUE_TYPE , PFT.JV_FLIGHT_CARRIER_CODE AS JV_FLIGHT_CARRIER_CODE , PPT.PORT_TONNAGE_UID AS PORT_TONNAGE_UID , PPT.AWB_UID AS AWB_UID , PIS.INVOICE_SEPARATION_UID AS INVOICE_SEPARATION_UID , PFT.FLIGHT_TONNAGE_UID AS FLIGHT_TONNAGE_UID FROM PN_FLT_TONNAGES PFT , FZ_AIRLINES FA , PN_TONNAGE_FLT_PORTS PTFP , PN_PORT_TONNAGES PPT , FF_AIRCRAFT_SERVICE_TYPES FAST , SR_PN_INVOICE_SEPARATIONS PIS --new , SR_PN_INVOICE_SEP_DETAILS PISD--new , SR_PN_INV_SEP_PORT_TONNAGES PISPT --new WHERE PFT.FLIGHT_OPERATION_DATE >= trunc( CASE :rundate WHEN TO_DATE('01/01/1900', 'DD/MM/YYYY') THEN ADD_MONTHS(SYSDATE,-1) ELSE ADD_MONTHS(:rundate,-1) END, 'MON') AND PFT.FLIGHT_OPERATION_DATE < trunc( CASE :rundate WHEN TO_DATE('01/01/1900', 'DD/MM/YYYY') THEN TRUNC(SYSDATE) ELSE TRUNC(:rundate) END, 'MON') AND PFT.TYPE IN ('C', 'F') AND PFT.RECORD_TYPE = 'M' AND (PFT.TERMINAL_OPERATOR NOT IN ('X', 'A') OR (PFT.TERMINAL_OPERATOR <> 'X' AND FA.CARRIER_CODE IN (SELECT * FROM SPECIAL_HANDLING_AIRLINE) AND PPT.REVENUE_TYPE IN (SELECT * FROM SPECIAL_REVENUE_TYPE) AND PPT.SHIPMENT_FLOW_TYPE IN (SELECT * FROM SPECIAL_SHIPMENT_FLOW_TYPE) AND PFT.FLIGHT_OPERATION_DATE >= (select EFF_DATE from SPECIAL_HANDLING_EFF_DATE) )) AND PFT.DELETING_DATETIME IS NULL AND FA.AIRLINE_UID = PFT.AIRLINE_UID AND FA.DELETING_DATETIME IS NULL AND PTFP.FLIGHT_TONNAGE_UID = PFT.FLIGHT_TONNAGE_UID AND PTFP.RECORD_TYPE = 'M' AND PTFP.DELETING_DATETIME IS NULL AND PPT.TONNAGE_FLIGHT_PORT_UID (+)= PTFP.TONNAGE_FLIGHT_PORT_UID AND PPT.RECORD_TYPE (+)= 'M' AND PPT.DISCREPANCY_TYPE (+)= 'NONE' AND PPT.ADJUSTMENT_INC_FLAG (+)= 'Y' AND PPT.DELETING_DATETIME (+) IS NULL AND FAST.AIRCRAFT_SERVICE_TYPE_UID = PFT.AIRCRAFT_SERVICE_TYPE_UID AND FAST.DELETING_DATETIME IS NULL AND PIS.TEMPORAL_NAME = TO_CHAR((CASE :rundate --new WHEN TO_DATE('01/01/1900', 'DD/MM/YYYY') THEN TRUNC(SYSDATE) ELSE TRUNC(:rundate) END ), 'YYYYMM') || '00' AND PIS.INVOICE_SEPARATION_UID = PISD.INVOICE_SEPARATION_UID --new AND PISD.INVOICE_SEP_DETAIL_UID = PISPT.INVOICE_SEP_DETAIL_UID --new AND PISPT.PORT_TONNAGE_UID = PPT.PORT_TONNAGE_UID --new AND PIS.PRINT_SUPPORTING_DOC = 'Y';上面是oracle的写法,请转成spark SQL的写法。

2023-06-02 上传

select * from ( select row_.*, rownum rownum_ from ( select * from ( select distinct OB.BUSI_ORDER_ID, 0 as HIS_ID, OB.BUSI_CODE, OB.CUST_ID, OB.CEASE_REASON, OB.ORDER_STATE, OB.CHANNEL_TYPE, ob.user_id, OB.IS_BATCH_ORDER, OB.APPLICATION_ID, OB.CREATE_DATE, OB.DONE_DATE, OB.EFF_DATE, OB.EXP_DATE, OB.OPER_ID, OB.ORG_ID, OB.REGION_ID, OB.NOTE, OB.PROCESS_STATE, nvl(oi.cust_name, ic.cust_name) cust_name, nvl(oc.icc_id, iu.icc_id) icc_id, nvl(oc.svc_num, iu.svc_num) svc_num, icp.cust_name parent_cust_name, icp.cust_id parent_cust_id, ol.order_list_id from ord_busi ob left join ord_offer oo on oo.busi_order_id = ob.busi_order_id and ob.user_id = oo.user_id left join info_user iu on oo.user_id = iu.user_id left join info_cust ic on ob.cust_id = ic.cust_id left join ord_cust oi on ob.cust_id = oi.cust_id and ob.busi_order_id = oi.busi_order_id left join info_cust icp on nvl(ic.parent_cust_id, oi.parent_cust_id) = icp.cust_id left join ( SELECT * FROM ord_user WHERE user_order_id IN ( SELECT MAX(user_order_id) user_order_id FROM ord_user GROUP BY busi_order_id,user_id ) ) oc on ob.user_id = oc.user_id and ob.busi_order_id = oc.busi_order_id left join ord_list ol on ob.busi_order_id = ol.busi_order_id WHERE 1 = 1 and OB.CUST_ID IN( SELECT DISTINCT CUST_ID FROM (SELECT CUST_ID, PARENT_CUST_ID FROM INFO_CUST UNION SELECT CUST_ID, PARENT_CUST_ID FROM ORD_CUST) TMP START WITH TMP.CUST_ID = '10001009208' CONNECT BY TMP.PARENT_CUST_ID = PRIOR TMP.CUST_ID ) union all select distinct OB.BUSI_ORDER_ID,OB.HIS_ID, OB.BUSI_CODE, OB.CUST_ID, OB.CEASE_REASON, OB.ORDER_STATE, OB.CHANNEL_TYPE, OB.USER_ID, OB.IS_BATCH_ORDER, OB.APPLICATION_ID, OB.CREATE_DATE, OB.DONE_DATE, OB.EFF_DATE, OB.EXP_DATE, OB.OPER_ID, OB.ORG_ID, OB.REGION_ID, OB.NOTE, OB.PROCESS_STATE, nvl(oi.cust_name,ic.cust_name) cust_name , nvl(oc.icc_id, iu.icc_id) icc_id, nvl(oc.svc_num,iu.svc_num) svc_num, icp.cust_name parent_cust_name, icp.cust_id parent_cust_id, ol.order_list_id from ord_busi_his ob left join ord_offer_his oo on oo.busi_order_id = ob.busi_order_id 优化一下

2023-06-02 上传