堆栈内存溢出
  繁体   English   中英

CASE 表达式中引用的 CTE 返回 null 个值。 我的 CTE 作为独立查询正常工作

[英]Referenced CTE in CASE expression is returning null values. My CTE works correctly as standalone query

 原文  2022-09-26 19:47:43  3   1    sql-server/ tsql/ case/ common-table-expression/ sql-null

问题描述

我有一个按预期工作的查询，我需要在它的基础上构建一个包含具有条件值的新列。 新列的结果是日期或字符串“na”。 为此，我编写了一个 CASE 语句，然后在该语句中引用 CTE 以提供条件逻辑。

主查询（不添加 CASE 语句）作为独立查询工作，CTE 正常工作并在作为独立查询运行时提供正确的日期。

这是我第一次包含 INSERT 语句。 如果我搞砸了，请告诉我。

主查询表：

CREATE TABLE mainquery(
   Region_ID       INTEGER  NOT NULL PRIMARY KEY
  ,messageid       INTEGER  NOT NULL
  ,name            VARCHAR(50) NOT NULL
  ,DateReceived    DATETIME  NOT NULL
  ,Datemodified    DATETIME  NOT NULL
  ,Messagestatus   INTEGER  NOT NULL
  ,clientid        VARCHAR(255)
  ,ClientFirstName VARCHAR(255) NOT NULL
  ,ClientLastName  VARCHAR(255) NOT NULL
  ,clientdob       DATETIME  NOT NULL
  ,Supervisorid    INTEGER  NOT NULL
  ,visitid         VARCHAR(255) NOT NULL
  ,SuperName       VARCHAR(255) NOT NULL
  ,SuperID         VARCHAR(255) NOT NULL
  ,colldate        VARCHAR(255) NOT NULL
  ,colltime        VARCHAR(255) NOT NULL
  ,Ordername       VARCHAR(255) NOT NULL
  ,errorlogs       VARCHAR(8000) NOT NULL
  ,comments        VARCHAR(255)
  ,last_visit_date DATETIME
);
INSERT INTO mainquery(Region_ID,messageid,name,DateReceived,Datemodified,Messagestatus,clientid,ClientFirstName,ClientLastName,clientdob,Supervisorid,visitid,SuperName,SuperID,colldate,colltime,Ordername,errorlogs,comments,last_visit_date) VALUES (1,116113842,'R1_OG','2022-06-09 13:07:52.000','2022-06-09 13:07:52.000',4,'123456789','Fake','Name','1980-01-01  00:00:00.000',123,'741852963','Joe','J1234','2022-05-06','16:27:00','fake_order','Supervisor Match not found',NULL,NULL);
INSERT INTO mainquery(Region_ID,messageid,name,DateReceived,Datemodified,Messagestatus,clientid,ClientFirstName,ClientLastName,clientdob,Supervisorid,visitid,SuperName,SuperID,colldate,colltime,Ordername,errorlogs,comments,last_visit_date) VALUES (2,159753205,'SEL North','2022-03-12 04:07:85.000','2018-06-25 12:07:00.000',2,'963741258','Funny','Namely','1999-02-03 00:00:00.000',98524,'159654','David','DL652','2018-01-24','09:03:00','real_fake','Supervisor Match not found',NULL,NULL);
INSERT INTO mainquery(Region_ID,messageid,name,DateReceived,Datemodified,Messagestatus,clientid,ClientFirstName,ClientLastName,clientdob,Supervisorid,visitid,SuperName,SuperID,colldate,colltime,Ordername,errorlogs,comments,last_visit_date) VALUES (3,951789369,'Blue_South','2022-03-11 12:08:33.000','2022-03-11 12:08:33.001',2,NULL,'Who','Ami','2000-08-11 00:00:00.000',789456,'963123','Shirley','S852','2017-05-14','09:30:00','example_order','Client Match not found','here is a comment','na');
INSERT INTO mainquery(Region_ID,messageid,name,DateReceived,Datemodified,Messagestatus,clientid,ClientFirstName,ClientLastName,clientdob,Supervisorid,visitid,SuperName,SuperID,colldate,colltime,Ordername,errorlogs,comments,last_visit_date) VALUES (4,294615883,'Mtn-Dew','2017-09-06 16:20:00.000','2017-09-06 16:20:00.001',2,NULL,'Why','Tho','1970-11-20 00:00:00.000',9631475,'159654852','Bob','B420','2022-09-22','10:25:31','example_example','Client Match not found',NULL,'na');
INSERT INTO mainquery(Region_ID,messageid,name,DateReceived,Datemodified,Messagestatus,clientid,ClientFirstName,ClientLastName,clientdob,Supervisorid,visitid,SuperName,SuperID,colldate,colltime,Ordername,errorlogs,comments,last_visit_date) VALUES (5,789963258,'Home-Base','2022-07-11 15:22:40.000','2022-07-11 15:22:40.001',2,NULL,'Where','Aru','1987-01-06 00:00:00.000',805690123,'805460378','Carlos','C999','2022-07-11','07:30:45','order_order','Client Match not found',NULL,'na');

CTE临时表：

CREATE TABLE CTE(
   uid        INTEGER  NOT NULL PRIMARY KEY
  ,clientdob  DATETIME  NOT NULL
  ,clienttype INTEGER  NOT NULL
  ,date       DATETIME  NOT NULL
  ,visitid    VARCHAR(255) NOT NULL
  ,Region_ID  INTEGER  NOT NULL
  ,facilityid INTEGER  NOT NULL
  ,locationid INTEGER  NOT NULL
);
INSERT INTO CTE(uid,clientdob,clienttype,date,visitid,Region_ID,facilityid,locationid) VALUES (123456789,'1980-01-01  00:00:00.000',3,'2022-09-18 00:00:00.000','741852963',1,240,32);
INSERT INTO CTE(uid,clientdob,clienttype,date,visitid,Region_ID,facilityid,locationid) VALUES (963741258,'1999-02-03 00:00:00.000',3,'2022-05-11 00:00:00.000','159654',2,606,123);
INSERT INTO CTE(uid,clientdob,clienttype,date,visitid,Region_ID,facilityid,locationid) VALUES (852654320,'1994-05-11 00:00:00.000',3,'2019-03-18 00:00:00.000','123456',3,632,12);
INSERT INTO CTE(uid,clientdob,clienttype,date,visitid,Region_ID,facilityid,locationid) VALUES (85360123,'1997-08-16 00:00:00.000',3,'2021-02-19 00:00:00.000','7896451',4,856,147);
INSERT INTO CTE(uid,clientdob,clienttype,date,visitid,Region_ID,facilityid,locationid) VALUES (85311456,'1964-10-31 00:00:00.000',3,'2016-02-14 00:00:00.000','85263',5,852,15);

预期视图：

宽表屏幕截图编辑添加：我对“预期视图”屏幕截图感到困惑。 屏幕截图显示了表格现在的样子的示例。 所需的视图是last_visit_date中有日期（在适当的行中），而不是 Null。

我的问题如下：查询仍然适用于新的 CASE 语句和 CTE，只是它没有在新列中提供正确的日期，而是返回 Null 值。

我是不是用错误的想法来处理这个查询？ 我以为我走在正确的道路上，但现在我怀疑自己。 我尝试使用子查询而不是 CTE，但我收到一条错误消息，指出由于每行有多个结果，查询无法完成。

这是我的主要查询和相关的 CTE：

WITH last_visit (uid, clientdob, clienttype, date, visitid, Region_ID, facilityid, locationid) AS
(
    SELECT DISTINCT 
        u.uid, u.clientdob, u.clienttype, 
        CONVERT(varchar, v.date) AS last_visit, 
        v.visitid, u.Region_ID, v.facilityid, v.locationid
    FROM 
        users u
    LEFT JOIN 
        visit v ON u.uid = v.clientid
                AND u.Region_ID = v.Region_ID
    WHERE 
        v.date = (SELECT MAX(v.date) FROM visit v WHERE v.clientid = u.uid)
        AND u.clienttype = 3
        AND u.uid <> 8663
        AND u.ulname NOT LIKE '%test%'
        AND u.ulname NOT LIKE '%unidentified%'
        AND u.delflvg = 0
        AND v.visittype = 1
        AND v.facilityid <> 0
        AND v.deleteflag = 0
)
SELECT 
    r.Region_ID, r.messageid, l.name, r.DateReceived, r.DateModified, 
    r.MessageStatus, r.clientid, r.ClientFirstName, r.ClientLastName, r.clientdob, 
    r.Supervisorid, r.visitid, r.SuperName, r.SuperID, r.colldate, r.colltime, 
    r.OrderName, r.errorlogs, a.comments,
    CASE 
        WHEN r.errorlogs LIKE 'Supervisor Match not found' 
            THEN lv.date 
            ELSE 'na' 
    END AS last_visit_date
FROM
    electronicresults r
JOIN 
    recelectronicresults a ON r.messageid = a.messageid 
                           AND r.Region_ID = a.Region_ID
LEFT OUTER JOIN 
    users u ON r.clientid = u.uid
LEFT OUTER JOIN 
    visit v ON r.clientid = v.clientid AND r.visitid = v.visitid
LEFT OUTER JOIN 
    last_visit lv ON r.visitid = lv.visitid 
                  AND r.clientid = lv.uid
JOIN 
    lblist l ON r.lbid = l.id 
             AND r.Region_ID = l.Region_ID
WHERE 
    r.MessageStatus IN (0, 2, 4)
    AND a.actiontaken = 0
    AND l.deleteflag = 0
GROUP BY 
    r.Region_ID, r.messageid, l.name, r.DateReceived, r.DateModified, 
    r.MessageStatus, r.clientid, r.ClientFirstName, r.ClientLastName, 
    r.clientdob, r.Supervisorid, r.visitid, r.SuperName, r.SuperID, 
    r.colldate, r.colltime, r.OrderName, r.errorlogs, a.comments, lv.date

感谢您花时间阅读本文，非常感谢任何支持、提示和技巧

1 个解决方案

解决方案1
 0  2023-01-10 21:54:05

当您提供一个脚本来创建表和示例数据时，我满怀希望，但不幸的是，您提供的脚本不起作用 - 您不能像指出的那样在DATETIME列中INSERT值“na”。 此外，示例DATETIME值之一无效：'2022-03-12 04:07:85.000'（没有 85 秒的时间）。 无论如何，我纠正了问题并继续前进。

您的示例查询中存在一个问题 - CASE语句在一种情况下返回DATETIME ，在另一种情况下返回VARCHAR 。 这是不合法的——所有情况都必须返回相同的数据类型。 我没有返回 'na'，而是选择了NULL 。

一旦我注释掉所有你没有包含的表，我就能够得到一个正在运行的查询：


CREATE TABLE mainquery(
   Region_ID       INTEGER  NOT NULL PRIMARY KEY
  ,messageid       INTEGER  NOT NULL
  ,name            VARCHAR(50) NOT NULL
  ,DateReceived    DATETIME  NOT NULL
  ,Datemodified    DATETIME  NOT NULL
  ,Messagestatus   INTEGER  NOT NULL
  ,clientid        VARCHAR(255)
  ,ClientFirstName VARCHAR(255) NOT NULL
  ,ClientLastName  VARCHAR(255) NOT NULL
  ,clientdob       DATETIME  NOT NULL
  ,Supervisorid    INTEGER  NOT NULL
  ,visitid         VARCHAR(255) NOT NULL
  ,SuperName       VARCHAR(255) NOT NULL
  ,SuperID         VARCHAR(255) NOT NULL
  ,colldate        VARCHAR(255) NOT NULL
  ,colltime        VARCHAR(255) NOT NULL
  ,Ordername       VARCHAR(255) NOT NULL
  ,errorlogs       VARCHAR(8000) NOT NULL
  ,comments        VARCHAR(255)
  ,last_visit_date DATETIME
);
INSERT INTO mainquery(Region_ID,messageid,name,DateReceived,Datemodified,Messagestatus,clientid,ClientFirstName,ClientLastName,clientdob,Supervisorid,visitid,SuperName,SuperID,colldate,colltime,Ordername,errorlogs,comments,last_visit_date) VALUES (1,116113842,'R1_OG','2022-06-09 13:07:52.000','2022-06-09 13:07:52.000',4,'123456789','Fake','Name','1980-01-01  00:00:00.000',123,'741852963','Joe','J1234','2022-05-06','16:27:00','fake_order','Supervisor Match not found',NULL,NULL);
INSERT INTO mainquery(Region_ID,messageid,name,DateReceived,Datemodified,Messagestatus,clientid,ClientFirstName,ClientLastName,clientdob,Supervisorid,visitid,SuperName,SuperID,colldate,colltime,Ordername,errorlogs,comments,last_visit_date) VALUES (2,159753205,'SEL North','2022-03-12 04:07:55.000','2018-06-25 12:07:00.000',2,'963741258','Funny','Namely','1999-02-03 00:00:00.000',98524,'159654','David','DL652','2018-01-24','09:03:00','real_fake','Supervisor Match not found',NULL,NULL);
INSERT INTO mainquery(Region_ID,messageid,name,DateReceived,Datemodified,Messagestatus,clientid,ClientFirstName,ClientLastName,clientdob,Supervisorid,visitid,SuperName,SuperID,colldate,colltime,Ordername,errorlogs,comments,last_visit_date) VALUES (3,951789369,'Blue_South','2022-03-11 12:08:33.000','2022-03-11 12:08:33.001',2,NULL,'Who','Ami','2000-08-11 00:00:00.000',789456,'963123','Shirley','S852','2017-05-14','09:30:00','example_order','Client Match not found','here is a comment',NULL);
INSERT INTO mainquery(Region_ID,messageid,name,DateReceived,Datemodified,Messagestatus,clientid,ClientFirstName,ClientLastName,clientdob,Supervisorid,visitid,SuperName,SuperID,colldate,colltime,Ordername,errorlogs,comments,last_visit_date) VALUES (4,294615883,'Mtn-Dew','2017-09-06 16:20:00.000','2017-09-06 16:20:00.001',2,NULL,'Why','Tho','1970-11-20 00:00:00.000',9631475,'159654852','Bob','B420','2022-09-22','10:25:31','example_example','Client Match not found',NULL,NULL);
INSERT INTO mainquery(Region_ID,messageid,name,DateReceived,Datemodified,Messagestatus,clientid,ClientFirstName,ClientLastName,clientdob,Supervisorid,visitid,SuperName,SuperID,colldate,colltime,Ordername,errorlogs,comments,last_visit_date) VALUES (5,789963258,'Home-Base','2022-07-11 15:22:40.000','2022-07-11 15:22:40.001',2,NULL,'Where','Aru','1987-01-06 00:00:00.000',805690123,'805460378','Carlos','C999','2022-07-11','07:30:45','order_order','Client Match not found',NULL,NULL);


CREATE TABLE CTE(
   uid        INTEGER  NOT NULL PRIMARY KEY
  ,clientdob  DATETIME  NOT NULL
  ,clienttype INTEGER  NOT NULL
  ,date       DATETIME  NOT NULL
  ,visitid    VARCHAR(255) NOT NULL
  ,Region_ID  INTEGER  NOT NULL
  ,facilityid INTEGER  NOT NULL
  ,locationid INTEGER  NOT NULL
);
INSERT INTO CTE(uid,clientdob,clienttype,date,visitid,Region_ID,facilityid,locationid) VALUES (123456789,'1980-01-01  00:00:00.000',3,'2022-09-18 00:00:00.000','741852963',1,240,32);
INSERT INTO CTE(uid,clientdob,clienttype,date,visitid,Region_ID,facilityid,locationid) VALUES (963741258,'1999-02-03 00:00:00.000',3,'2022-05-11 00:00:00.000','159654',2,606,123);
INSERT INTO CTE(uid,clientdob,clienttype,date,visitid,Region_ID,facilityid,locationid) VALUES (852654320,'1994-05-11 00:00:00.000',3,'2019-03-18 00:00:00.000','123456',3,632,12);
INSERT INTO CTE(uid,clientdob,clienttype,date,visitid,Region_ID,facilityid,locationid) VALUES (85360123,'1997-08-16 00:00:00.000',3,'2021-02-19 00:00:00.000','7896451',4,856,147);
INSERT INTO CTE(uid,clientdob,clienttype,date,visitid,Region_ID,facilityid,locationid) VALUES (85311456,'1964-10-31 00:00:00.000',3,'2016-02-14 00:00:00.000','85263',5,852,15);


SELECT 
    r.Region_ID, r.messageid, r.DateReceived, r.DateModified, 
    r.MessageStatus, r.clientid, r.ClientFirstName, r.ClientLastName, r.clientdob, 
    r.Supervisorid, r.visitid, r.SuperName, r.SuperID, r.colldate, r.colltime, 
    r.OrderName, r.errorlogs, 
    CASE 
        WHEN r.errorlogs LIKE 'Supervisor Match not found' 
            THEN lv.date 
            ELSE NULL 
    END AS last_visit_date
FROM
    mainquery r
LEFT OUTER JOIN 
    CTE lv ON r.visitid = lv.visitid 
                  AND r.clientid = lv.uid
WHERE 
    r.MessageStatus IN (0, 2, 4)
GROUP BY 
    r.Region_ID, r.messageid, r.DateReceived, r.DateModified, 
    r.MessageStatus, r.clientid, r.ClientFirstName, r.ClientLastName, 
    r.clientdob, r.Supervisorid, r.visitid, r.SuperName, r.SuperID, 
    r.colldate, r.colltime, r.OrderName, r.errorlogs, lv.date

这是 output：

地区_ID 消息ID 接收日期 修改日期 消息状态 客户编号 客户名字 客户姓氏 客户端 主管 访问ID 超名 超级ID 约会对象 科莱姆 订单名称 错误日志 上次访问日期
1个 116113842 2022-06-09 13:07:52.000 2022-06-09 13:07:52.000 4个 123456789 伪造的 名称 1980-01-01 00:00:00.000 123 741852963 乔 J1234 2022-05-06 16:27:00 假订单 未找到主管匹配 2022-09-18 00:00:00.000
2个 159753205 2022-03-12 04:07:55.000 2018-06-25 12:07:00.000 2个 963741258 有趣的 即 1999-02-03 00:00:00.000 98524 159654 大卫 DL652 2018-01-24 09:03:00 真假 未找到主管匹配 2022-05-11 00:00:00.000
3个 951789369 2022-03-11 12:08:33.000 2022-03-11 12:08:33.000 2个 NULL 谁 阿美 2000-08-11 00:00:00.000 789456 963123 雪莉 S852 2017-05-14 09:30:00 示例_订单 未找到匹配的客户 NULL
4个 294615883 2017-09-06 16:20:00.000 2017-09-06 16:20:00.000 2个 NULL 为什么 寿 1970-11-20 00:00:00.000 9631475 159654852 鲍勃 B420 2022-09-22 10:25:31 例子_例子 未找到匹配的客户 NULL
5个 789963258 2022-07-11 15:22:40.000 2022-07-11 15:22:40.000 2个 NULL 在哪里 阿鲁 1987-01-06 00:00:00.000 805690123 805460378 卡洛斯 C999 2022-07-11 07:30:45 order_order 未找到匹配的客户 NULL

同样，您必须重新添加我必须删除的JOIN s，因为未包含表以及SELECT列表中的某些项目、 WHERE子句和“GROUP BY”子句。

暂无
暂无

声明:本站的技术帖子网页，遵循CC BY-SA 4.0协议，如果您需要转载，请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.

相关问题 CTE未返回预期值 CTE 查询不返回任何结果 LEFT JOIN CTE作为Lambda表达式/查询表达式 带有额外日期查找的 CTE 返回 NULL 公用表表达式 (CTE) 查询中的表行计数？ 如何使用CTE和联接优化查询 Hive CTE，我可以查询表中的值吗？ 为什么我的 upperRange2 列偶尔返回 NULL。 我在滥用 CTE 吗？ SQL Server CTE 查询重复值 CASE或IF Inside CTE语句
相关标签
 
粤ICP备18138465号  © 2020-2024 STACKOOM.COM