CASE WHEN IFNULL( t_temp.id, 0 ) = 0 THEN "" ELSE "selected" END AS "selected"

时间: 2023-10-29 08:07:29 浏览: 22
This SQL statement is using the CASE WHEN function to check if the value of IFNULL( t_temp.id, 0 ) equals 0. If it does, then an empty string is returned. If it does not, then the string "selected" is returned. The result of this statement is an additional column in the output of a SQL query that indicates whether a certain value is selected or not.
相关问题

CASE WHEN IFNULL( t_temp.id, 0 ) = 0 THEN "" ELSE "selected" END AS "selected"用中文解释

这段代码的意思是:如果t_temp.id为空,则返回空字符串,否则返回"selected"。其中,IFNULL函数用于判断t_temp.id是否为空,如果为空则返回0,否则返回t_temp.id的值。而CASE WHEN语句用于根据条件返回不同的值。最终结果为一个名为"selected"的字段,该字段的值为""或"selected"。

Oracle 下SQL语句怎么写 SELECT @ROWNUM := @ROWNUM + 1 AS TEMPRANK, @INCRNUM := CASE WHEN @ROWTOTAL = OBJ.YLCOUNT + 1 THEN @INCRNUM WHEN @ROWTOTAL := OBJ.YLCOUNT + 1 THEN @ROWNUM END AS FILERANK, OBJ.* FROM ( SELECT DOCINFO.TITLE, DOCINFO.DOC_ID AS DOCID, DOCINFO.DOC_TYPE AS DOCTYPE, U.USER_NAME AS AUTHORNAME, CONCAT( U.USER_NAME, '/', CASE WHEN O.SHORT_NAME = '' THEN '无' ELSE O.SHORT_NAME END ) AS USERNAME, IFNULL( DOCINFO.DOWNLOAD_NUM, 0 ) AS YLCOUNT FROM DOC_INFO DOCINFO, SYS_USERS U, SYS_ORGAN O, sys_stru WHERE DOCINFO.VALID_FLAG = '1' AND IFNULL( DOCINFO.DOWNLOAD_NUM, 0 ) != 0 AND U.USER_ID = DOCINFO.AUTHOR_ID AND sys_stru.STRU_ID = U.DEPARTMENT_ID AND O.ORGAN_ID = sys_stru.ORGAN_ID GROUP BY DOCINFO.DOC_ID, U.USER_NAME ORDER BY DOCINFO.DOWNLOAD_NUM DESC, DOCINFO.TITLE DESC ) OBJ, ( SELECT @ROWNUM := 0, @ROWTOTAL := NULL, @INCRNUM := 0 ) R

在 Oracle 中,可以将该 SQL 语句写成如下形式: ``` SELECT TEMPRANK, FILERANK, TITLE, DOCID, DOCTYPE, AUTHORNAME, USERNAME, YLCOUNT FROM ( SELECT DOCINFO.TITLE, DOCINFO.DOC_ID AS DOCID, DOCINFO.DOC_TYPE AS DOCTYPE, U.USER_NAME AS AUTHORNAME, CONCAT(U.USER_NAME, '/', CASE WHEN O.SHORT_NAME = '' THEN '无' ELSE O.SHORT_NAME END) AS USERNAME, IFNULL(DOCINFO.DOWNLOAD_NUM, 0) AS YLCOUNT, @ROWNUM := @ROWNUM + 1 AS TEMPRANK, @INCRNUM := CASE WHEN @ROWTOTAL = OBJ.YLCOUNT + 1 THEN @INCRNUM WHEN @ROWTOTAL := OBJ.YLCOUNT + 1 THEN @ROWNUM END AS FILERANK FROM DOC_INFO DOCINFO, SYS_USERS U, SYS_ORGAN O, sys_stru WHERE DOCINFO.VALID_FLAG = '1' AND IFNULL(DOCINFO.DOWNLOAD_NUM, 0) != 0 AND U.USER_ID = DOCINFO.AUTHOR_ID AND sys_stru.STRU_ID = U.DEPARTMENT_ID AND O.ORGAN_ID = sys_stru.ORGAN_ID GROUP BY DOCINFO.DOC_ID, U.USER_NAME ORDER BY DOCINFO.DOWNLOAD_NUM DESC, DOCINFO.TITLE DESC ) OBJ, (SELECT @ROWNUM := 0, @ROWTOTAL := NULL, @INCRNUM := 0) R; ``` 在 Oracle 中,变量需要在 SQL 语句外面进行声明和初始化。这里使用了 `@ROWNUM`、`@ROWTOTAL` 和 `@INCRNUM` 三个变量,它们都在 SQL 语句的最后一行进行了声明和初始化。 此外,由于 Oracle 对于 SQL 语句的执行顺序与 MySQL 略有不同,因此需要将临时变量的计算放在子查询中,并使用外层查询来获取这些变量的值。最终的结果集是从子查询中返回的。

相关推荐

SELECT ak.dept_id deptId,ak.dept_name deptName,ak.parent_id parentId, IFNULL(pk.primaryShould,0) primaryShould,IFNULL(pk.primaryNot,0) primaryNot,IFNULL(pk.primaryGraduated,0) primaryGraduated, IFNULL(mk.middleShould,0) middleShould,IFNULL(mk.middleNot,0) middleNot,IFNULL(mk.middleGraduated,0) middleGraduated, IFNULL(hk.highShould,0) highShould,IFNULL(hk.highGraduated,0) highGraduated,IFNULL(hk.highNot,0) highNot FROM sys_dept ak LEFT JOIN (SELECT subordinate_school, SUM(CASE WHEN grade = 6 THEN 1 ELSE 0 END) primaryShould, SUM(CASE WHEN grade = 6 AND is_graduation = 'N' THEN 1 ELSE 0 END) primaryNot, SUM(CASE WHEN grade = 6 AND is_graduation = 'Y' THEN 1 ELSE 0 END) primaryGraduated FROM primary_school_roll WHERE primary_student_id LIKE concat('20', '%') GROUP BY subordinate_school) pk ON ak.dept_id = pk.subordinate_school LEFT JOIN (SELECT subordinate_school, SUM(CASE WHEN grade = 9 THEN 1 ELSE 0 END) middleShould, SUM(CASE WHEN grade = 9 AND is_graduation = 'N' THEN 1 ELSE 0 END) middleNot, SUM(CASE WHEN grade = 9 AND is_graduation = 'Y' THEN 1 ELSE 0 END) middleGraduated FROM middle_school_roll WHERE middle_student_id LIKE concat('20', '%') GROUP BY subordinate_school) mk ON ak.dept_id = mk.subordinate_school LEFT JOIN (SELECT subordinate_school, SUM(CASE WHEN grade = 12 THEN 1 ELSE 0 END) highShould, SUM(CASE WHEN graduation_way = '001' AND is_graduation = 'T' THEN 1 ELSE 0 END) highNot, SUM(CASE WHEN graduation_way = '000' AND is_graduation = 'Y' THEN 1 ELSE 0 END) highGraduated FROM high_school_roll WHERE high_student_id LIKE concat('20', '%') GROUP BY subordinate_school) hk ON ak.dept_id = hk.subordinate_school WHERE ak.state = 3 GROUP BY ak.dept_id

对于这个SQL查询语句的优化,可以考虑以下几点: 1. 使用JOIN语句代替子查询:将子查询转换为JOIN语句,可以提高查询性能。 2. 添加适当的索引:根据查询条件和连接条件,为相关表添加合适的索引,以加快查询速度。 3. 减少重复的条件判断:在子查询和主查询中,有一些条件判断是重复的,可以将它们提取出来,避免重复计算。 4. 使用表别名:为表和字段使用简短的别名,提高查询语句的可读性。 下面是对原始SQL查询语句进行优化的示例: SELECT DISTINCT A.DATA_TYPE AS DATA_TYPE, A.DATA_VALUE AS TSL, IFNULL(B.DATA_VALUE, 0) AS JBL, A.CURRENT_ID FROM YXDDZH_MIDDLE.GZ_SCREEN_JGSY_SDHJ_SPFW_CITY_AREA_DATA A LEFT JOIN ( SELECT DATA_TYPE, DATA_VALUE FROM YXDDZH_MIDDLE.GZ_SCREEN_JGSY_SDHJ_SPFW_CITY_AREA_DATA WHERE IS_DELETED = 0 AND DATA_DIMENSION = '期末' AND DATA_NAME = '举报' AND LEVEL = 2 AND DATA_AREA = '市级' AND DATA_TIME = ( SELECT MAX(DATA_TIME) FROM YXDDZH_MIDDLE.GZ_SCREEN_JGSY_SDHJ_SPFW_CITY_AREA_DATA WHERE IS_DELETED = 0 AND DATA_DIMENSION = '期末' AND DATA_NAME = '举报' AND LEVEL = 2 AND DATA_AREA = '市级' ) ) B ON A.DATA_TYPE = B.DATA_TYPE WHERE A.IS_DELETED = 0 AND A.DATA_DIMENSION = '期末' AND A.LEVEL = 2 AND A.DATA_NAME = '投诉' AND A.DATA_AREA = '市级' AND A.DATA_TIME = ( SELECT MAX(DATA_TIME) FROM YXDDZH_MIDDLE.GZ_SCREEN_JGSY_SDHJ_SPFW_CITY_AREA_DATA WHERE IS_DELETED = 0 AND DATA_DIMENSION = '期末' AND DATA_NAME = '投诉' AND LEVEL = 2 AND DATA_AREA = '市级' ); 请注意,具体的优化策略可能需要根据实际情况进行调整和测试,以达到最佳的查询性能。

优化以下SQL select pao.id, pao.order_no, pao.apply_time, pao.purchase_user_id, pao.purchase_user_name, pao.apply_user_id, pao.apply_user_name, pao.apply_department_id, pao.apply_department_name, pao.apply_end_time, pao.create_user_id, pao.create_user_name, pao.approve_type, pao.approve_user_id, pao.approve_user_name, pao.approve_time, pao.description, pao.order_type, pao.purchase_type, pao.storage_type, pao.compose_order_no, pao.company_id, pao.delete, pao.create_time, pao.update_time, pao.supplier_id, pao.image_path, pao.contract_id, pao.status, pao.invoice_signer_name, pao.total_amount, pao.total_amount_tax, pao.purchase_status, pao.cancel_reason, pao.print_status, pao.demand_id, pao.arrival_status, pao.supervise_num, pao.supervise_date, pao.merge_apply_id, pao.deadline, pao.remind , s.name as supplierName, paod.amount, cm.return_status as returnStatus, cm.inventory_status as inventoryStatus, cm.stock_remark, cm.merge_flag, cm.signature_file, cm.department_pass, cm.receipt_file, cm.amount_paid, cm.amount_unpaid, cm.contract_name, cm.status as contractStatus, cm.contract_no, cm.contract_amount, paod.product_name, cm.advance_payment, cm.advance_ratio, cm.currency_unit from purchase_apply_order pao left join supplier s on pao.supplier_id = s.id left join ( SELECT GROUP_CONCAT(distinct p.product_name) product_name, sum(IFNULL(amount_tax, 0)) amount, apply_order_no from purchase_apply_order_details pa left join product p on p.pn_code = pa.product_code where p.company_id = 29 GROUP BY apply_order_no ) paod on paod.apply_order_no = pao.order_no left join contract_management cm on pao.contract_id = cm.id where pao.delete = 0 and pao.company_id = 29 and deadline <= '2023-05-25 15:34:00.01' and remind = 0 and arrival_status in( 0 , 1 ) order by pao.create_time desc;

首先,我们可以对该 SQL 查询语句进行简化,只选择需要的字段而不是全部选择。其次,我们可以尝试添加索引以加快查询速度。 以下是优化后的 SQL 查询语句: SELECT pao.id, pao.order_no, pao.apply_time, pao.purchase_user_id, pao.purchase_user_name, pao.apply_user_id, pao.apply_user_name, pao.apply_department_id, pao.apply_department_name, pao.apply_end_time, pao.create_user_id, pao.create_user_name, pao.approve_type, pao.approve_user_id, pao.approve_user_name, pao.approve_time, pao.description, pao.order_type, pao.purchase_type, pao.storage_type, pao.compose_order_no, pao.company_id, pao.delete, pao.create_time, pao.update_time, pao.supplier_id, pao.image_path, pao.contract_id, pao.status, pao.invoice_signer_name, pao.total_amount, pao.total_amount_tax, pao.purchase_status, pao.cancel_reason, pao.print_status, pao.demand_id, pao.arrival_status, pao.supervise_num, pao.supervise_date, pao.merge_apply_id, pao.deadline, pao.remind, s.name AS supplierName, paod.amount, cm.return_status AS returnStatus, cm.inventory_status AS inventoryStatus, cm.stock_remark, cm.merge_flag, cm.signature_file, cm.department_pass, cm.receipt_file, cm.amount_paid, cm.amount_unpaid, cm.contract_name, cm.status AS contractStatus, cm.contract_no, cm.contract_amount, paod.product_name, cm.advance_payment, cm.advance_ratio, cm.currency_unit FROM purchase_apply_order pao LEFT JOIN supplier s ON pao.supplier_id = s.id LEFT JOIN ( SELECT GROUP_CONCAT(DISTINCT p.product_name) product_name, SUM(IFNULL(amount_tax, 0)) amount, apply_order_no FROM purchase_apply_order_details pa LEFT JOIN product p ON p.pn_code = pa.product_code WHERE p.company_id = 29 GROUP BY apply_order_no ) paod ON paod.apply_order_no = pao.order_no LEFT JOIN contract_management cm ON pao.contract_id = cm.id WHERE pao.delete = 0 AND pao.company_id = 29 AND deadline <= '2023-05-25 15:34:00.01' AND remind = 0 AND arrival_status IN (0, 1) ORDER BY pao.create_time DESC; 我们可以为 purchase_apply_order 表的 company_id 字段和 deadline 字段以及 remind 字段创建索引。同时,也可以为 arrival_status 字段和 delete 字段创建索引。这可以大大加快查询速度。 CREATE INDEX idx_purchase_apply_order_company_id_deadline_remind ON purchase_apply_order (company_id, deadline, remind); CREATE INDEX idx_purchase_apply_order_arrival_status_delete ON purchase_apply_order (arrival_status, delete);
优化后的SQL语句如下: SELECT CONCAT(HOUR(mail_send_time) DIV 1 * 1, ':00-', HOUR(mail_send_time) DIV 1 * 1, ':59') AS timeInterval, IFNULL(COUNT(*), 0) AS total, IFNULL(SUM(contact_account_type = (SELECT code_value FROM dwd_t_code_value WHERE code_type='contact_type' AND name='微信')), 0) AS wxTotal, IFNULL(SUM(contact_account_type = (SELECT code_value FROM dwd_t_code_value WHERE code_type='contact_type' AND name='QQ')), 0) AS qqTotal, IFNULL(SUM(local_action = (SELECT code_value FROM dwd_t_code_value WHERE code_type='local_action' AND name='发送') AND contact_account_type = (SELECT code_value FROM dwd_t_code_value WHERE code_type='contact_type' AND name='微信')), 0) AS wxSend, IFNULL(SUM(local_action = (SELECT code_value FROM dwd_t_code_value WHERE code_type='local_action' AND name='接收') AND contact_account_type = (SELECT code_value FROM dwd_t_code_value WHERE code_type='contact_type' AND name='微信')), 0) AS wxReceive, IFNULL(SUM(local_action = (SELECT code_value FROM dwd_t_code_value WHERE code_type='local_action' AND name='发送') AND contact_account_type = (SELECT code_value FROM dwd_t_code_value WHERE code_type='contact_type' AND name='QQ')), 0) AS qqSend, IFNULL(SUM(local_action = (SELECT code_value FROM dwd_t_code_value WHERE code_type='local_action' AND name='接收') AND contact_account_type = (SELECT code_value FROM dwd_t_code_value WHERE code_type='contact_type' AND name='QQ')), 0) AS qqReceive FROM dwd_t_friend_talk WHERE person_no = '653129200105072624' AND contact_account_type IN (SELECT code_value FROM dwd_t_code_value WHERE code_type='contact_type' AND name IN ('微信', 'QQ')) AND friend_account <> '' AND contact_account_type <> '' AND mail_send_time IS NOT NULL AND mail_send_time <> '' GROUP BY HOUR(mail_send_time) DIV 1; 改造后的SQL语句使用了子查询,通过dwd_t_code_value表获取contact_account_type和local_action字段的码值,从而将原本的汉字替换为了码值。

select * from (select city_name 城市名称 , county_name 城区名称 , street_name 街道名称 , living_quarter_name 小区名称 , pump_house_name 泵房名称 , case when pump_house_name='中骏西湖一号' and water_pressure_area is not null then concat('中骏西湖一号',water_pressure_area) else water_pressure_area end 水压分区 , concat(ifnull(living_quarter_name,''),ifnull(pump_house_name,''),ifnull(water_pressure_area,'整体')) 泵站 , idx_cal_time 时间 , case when idx_cal_period ='d' then DATE_FORMAT(idx_cal_time,'%Y-%m-%d') when idx_cal_period ='m' then DATE_FORMAT(idx_cal_time,'%Y-%m') when idx_cal_period ='y' then DATE_FORMAT(idx_cal_time,'%Y') else idx_cal_time end 采集时间 , stat_type_nm 指标名称 , case when stat_type_nm like '%压力%' then '出水压力' when stat_type_nm like '%供水%' then '供水量' when stat_type_nm like '%电耗%' then '电耗量' when stat_type_nm like '%电压%' then '电压' when stat_type_nm like '%电流%' then '电流' when stat_type_nm like '%频率%' then '频率' when stat_type_nm like '%功率%' then '功率' else '' end '指标类型' , case when stat_type_nm like '%压力%' then 'MPa' when stat_type_nm like '%供水%' then 'm³' when stat_type_nm like '%电耗%' then 'kW·h' when stat_type_nm like '%电压%' then 'V' when stat_type_nm like '%电流%' then 'A' when stat_type_nm like '%频率%' then 'Hz' when stat_type_nm like '%功率%' then 'kW' else '' end '单位' , round(idx_val,2) 指标值 , case idx_cal_period when 'h' then '每小时' when 'd' then '每天' when 'm' then '每月' else '每年' end 统计周期 from dm_ws_iot_opc_point_idx_stat )a这个sql语句能优化查询速度吗

最新推荐

【缺陷检测】基于matlab GUI印刷电路板自动缺陷检测【含Matlab源码 1912期】.mp4

CSDN佛怒唐莲上传的视频均有对应的完整代码,皆可运行,亲测可用,适合小白; 1、代码压缩包内容 主函数:main.m; 调用函数:其他m文件;无需运行 运行结果效果图; 2、代码运行版本 Matlab 2019b;若运行有误,根据提示修改;若不会,私信博主; 3、运行操作步骤 步骤一:将所有文件放到Matlab的当前文件夹中; 步骤二:双击打开main.m文件; 步骤三:点击运行,等程序运行完得到结果; 4、仿真咨询 如需其他服务,可私信博主或扫描博客文章底部QQ名片; 4.1 博客或资源的完整代码提供 4.2 期刊或参考文献复现 4.3 Matlab程序定制 4.4 科研合作

【图像处理】基于matlab GUI自动报靶系统(重弹孔)【含Matlab源码 973期】.mp4

CSDN佛怒唐莲上传的视频均有对应的完整代码,皆可运行,亲测可用,适合小白; 1、代码压缩包内容 主函数:main.m; 调用函数:其他m文件;无需运行 运行结果效果图; 2、代码运行版本 Matlab 2019b;若运行有误,根据提示修改;若不会,私信博主; 3、运行操作步骤 步骤一:将所有文件放到Matlab的当前文件夹中; 步骤二:双击打开main.m文件; 步骤三:点击运行,等程序运行完得到结果; 4、仿真咨询 如需其他服务,可私信博主或扫描博客文章底部QQ名片; 4.1 博客或资源的完整代码提供 4.2 期刊或参考文献复现 4.3 Matlab程序定制 4.4 科研合作

【人脸识别】基于matlab GUI模板匹配人脸识别【含Matlab源码 2533期】.mp4

CSDN佛怒唐莲上传的视频均有对应的完整代码,皆可运行,亲测可用,适合小白; 1、代码压缩包内容 主函数:main.m; 调用函数:其他m文件;无需运行 运行结果效果图; 2、代码运行版本 Matlab 2019b;若运行有误,根据提示修改;若不会,私信博主; 3、运行操作步骤 步骤一:将所有文件放到Matlab的当前文件夹中; 步骤二:双击打开main.m文件; 步骤三:点击运行,等程序运行完得到结果; 4、仿真咨询 如需其他服务,可私信博主或扫描博客文章底部QQ名片; 4.1 博客或资源的完整代码提供 4.2 期刊或参考文献复现 4.3 Matlab程序定制 4.4 科研合作

软件测试面试题.zip

软件测试面试题

定制linux内核(linux2.6.32)汇编.pdf

定制linux内核(linux2.6.32)汇编.pdf

管理建模和仿真的文件

管理Boualem Benatallah引用此版本:布阿利姆·贝纳塔拉。管理建模和仿真。约瑟夫-傅立叶大学-格勒诺布尔第一大学,1996年。法语。NNT:电话:00345357HAL ID:电话:00345357https://theses.hal.science/tel-003453572008年12月9日提交HAL是一个多学科的开放存取档案馆,用于存放和传播科学研究论文,无论它们是否被公开。论文可以来自法国或国外的教学和研究机构,也可以来自公共或私人研究中心。L’archive ouverte pluridisciplinaire

图像处理进阶:基于角点的特征匹配

# 1. 图像处理简介 ## 1.1 图像处理概述 图像处理是指利用计算机对图像进行获取、存储、传输、显示和图像信息的自动化获取和处理技术。图像处理的主要任务包括图像采集、图像预处理、图像增强、图像复原、图像压缩、图像分割、目标识别与提取等。 ## 1.2 图像处理的应用领域 图像处理广泛应用于医学影像诊断、遥感图像处理、安检领域、工业自动化、计算机视觉、数字图书馆、人脸识别、动作捕捉等多个领域。 ## 1.3 图像处理的基本原理 图像处理的基本原理包括数字图像的表示方式、基本的图像处理操作(如灰度变换、空间滤波、频域滤波)、图像分割、特征提取和特征匹配等。图像处理涉及到信号与系统、数字

Cannot resolve class android.support.constraint.ConstraintLayout

如果您在Android Studio中遇到`Cannot resolve class android.support.constraint.ConstraintLayout`的错误,请尝试以下解决方案: 1. 确认您的项目中是否添加了ConstraintLayout库依赖。如果没有,请在您的build.gradle文件中添加以下依赖: ```groovy dependencies { implementation 'com.android.support.constraint:constraint-layout:<version>' } ``` 其中`<version>`为您想要

Solaris常用命令_多路径配置.doc

Solaris常用命令_多路径配置.doc

"互动学习:行动中的多样性与论文攻读经历"

多样性她- 事实上SCI NCES你的时间表ECOLEDO C Tora SC和NCESPOUR l’Ingén学习互动,互动学习以行动为中心的强化学习学会互动,互动学习,以行动为中心的强化学习计算机科学博士论文于2021年9月28日在Villeneuve d'Asq公开支持马修·瑟林评审团主席法布里斯·勒菲弗尔阿维尼翁大学教授论文指导奥利维尔·皮耶昆谷歌研究教授:智囊团论文联合主任菲利普·普雷教授,大学。里尔/CRISTAL/因里亚报告员奥利维耶·西格德索邦大学报告员卢多维奇·德诺耶教授,Facebook /索邦大学审查员越南圣迈IMT Atlantic高级讲师邀请弗洛里安·斯特鲁布博士,Deepmind对于那些及时看到自己错误的人...3谢谢你首先,我要感谢我的两位博士生导师Olivier和Philippe。奥利维尔,"站在巨人的肩膀上"这句话对你来说完全有意义了。从科学上讲,你知道在这篇论文的(许多)错误中,你是我可以依