修改代码“select a.employee_id, case when count(a.employee_id) = 1 then a.department_id when count(a.employee_id) != 1 then b.department_id end as department_id from Employee as a left join( select employee_id, department_id from Employee where primary_flag = 'Y') as b group by a.employee_id;”

这段代码的作用是查询每个员工的部门ID，如果该员工只在一个部门工作，则直接使用该部门ID，否则使用主部门ID。

根据给定的代码，我做了一些修改，具体如下：

SELECT a.employee_id, 
       CASE 
           WHEN COUNT(DISTINCT b.department_id) = 1 THEN MAX(b.department_id)
           ELSE MAX(CASE WHEN b.primary_flag = 'Y' THEN b.department_id END)
       END AS department_id 
FROM Employee AS a 
LEFT JOIN Employee AS b ON a.employee_id = b.employee_id 
GROUP BY a.employee_id;

修改的思路如下：

1. 将子查询改为左连接原表，这样可以方便地处理每个员工在多个部门工作的情况；

2. 使用 MAX 函数结合 CASE 语句实现对部门ID的选择，如果该员工只在一个部门工作，则直接使用该部门ID；否则，使用主部门ID。

希望这次修改能够符合你的需求。

相关问题

编写存储过程 SELECT a.order_id, a.done_date, a.cust_id, a.subscriber_ins_id, a.access_num, c.dev_id, c.dev_name, c.corp_org, c.company_name, c.department_code, c.department_name, c.remarks FROM JOUR1.Om_Subscriber_202301 a LEFT JOIN JOUR1.om_order_202301 b ON a.order_id = b.order_id LEFT JOIN params1.sec_developer c ON b.dev_id = c.dev_id UNION ALL SELECT a.order_id, a.done_date, a.cust_id, a.subscriber_ins_id, a.access_num, c.dev_id, c.dev_name, c.corp_org, c.company_name, c.department_code, c.department_name, c.remarks FROM JOUR1.Om_Subscriber_202302 a LEFT JOIN JOUR1.om_order_202302 b ON a.order_id = b.order_id LEFT JOIN params1.sec_developer c ON b.dev_id = c.dev_id UNION ALL SELECT a.order_id, a.done_date, a.cust_id, a.subscriber_ins_id, a.access_num, c.dev_id, c.dev_name, c.corp_org, c.company_name, c.department_code, c.department_name, c.remarks FROM JOUR1.Om_Subscriber_202303 a LEFT JOIN JOUR1.om_order_202303 b ON a.order_id = b.order_id LEFT JOIN params1.sec_developer c ON b.dev_id = c.dev_id UNION ALL SELECT a.order_id, a.done_date, a.cust_id, a.subscriber_ins_id, a.access_num, c.dev_id, c.dev_name, c.corp_org, c.company_name, c.department_code, c.department_name, c.remarks FROM JOUR1.Om_Subscriber_202304 a LEFT JOIN JOUR1.om_order_202304 b ON a.order_id = b.order_id LEFT JOIN params1.sec_developer c ON b.dev_id = c.dev_id

你可以编写一个存储过程来执行这个查询。下面是一个示例：

CREATE OR REPLACE PROCEDURE get_data AS
BEGIN
  -- 创建临时表来保存结果
  CREATE GLOBAL TEMPORARY TABLE temp_data (
    order_id          NUMBER,
    done_date         DATE,
    cust_id           NUMBER,
    subscriber_ins_id NUMBER,
    access_num        VARCHAR2(100),
    dev_id            NUMBER,
    dev_name          VARCHAR2(100),
    corp_org          VARCHAR2(100),
    company_name      VARCHAR2(100),
    department_code   VARCHAR2(100),
    department_name   VARCHAR2(100),
    remarks           VARCHAR2(100)
  ) ON COMMIT PRESERVE ROWS;

  -- 第一个查询
  INSERT INTO temp_data
  SELECT a.order_id,
         a.done_date,
         a.cust_id,
         a.subscriber_ins_id,
         a.access_num,
         c.dev_id,
         c.dev_name,
         c.corp_org,
         c.company_name,
         c.department_code,
         c.department_name,
         c.remarks
  FROM JOUR1.Om_Subscriber_202301 a
  LEFT JOIN JOUR1.om_order_202301 b
    ON a.order_id = b.order_id
  LEFT JOIN params1.sec_developer c
    ON b.dev_id = c.dev_id;

  -- 后续查询使用UNION ALL连接
  INSERT INTO temp_data
  SELECT a.order_id,
         a.done_date,
         a.cust_id,
         a.subscriber_ins_id,
         a.access_num,
         c.dev_id,
         c.dev_name,
         c.corp_org,
         c.company_name,
         c.department_code,
         c.department_name,
         c.remarks
  FROM JOUR1.Om_Subscriber_202302 a
  LEFT JOIN JOUR1.om_order_202302 b
    ON a.order_id = b.order_id
  LEFT JOIN params1.sec_developer c
    ON b.dev_id = c.dev_id;

  INSERT INTO temp_data
  SELECT a.order_id,
         a.done_date,
         a.cust_id,
         a.subscriber_ins_id,
         a.access_num,
         c.dev_id,
         c.dev_name,
         c.corp_org,
         c.company_name,
         c.department_code,
         c.department_name,
         c.remarks
  FROM JOUR1.Om_Subscriber_202303 a
  LEFT JOIN JOUR1.om_order_202303 b
    ON a.order_id = b.order_id
  LEFT JOIN params1.sec_developer c
    ON b.dev_id = c.dev_id;

  INSERT INTO temp_data
  SELECT a.order_id,
         a.done_date,
         a.cust_id,
         a.subscriber_ins_id,
         a.access_num,
         c.dev_id,
         c.dev_name,
         c.corp_org,
         c.company_name,
         c.department_code,
         c.department_name,
         c.remarks
  FROM JOUR1.Om_Subscriber_202304 a
  LEFT JOIN JOUR1.om_order_202304 b
    ON a.order_id = b.order_id
  LEFT JOIN params1.sec_developer c
    ON b.dev_id = c.dev_id;

  -- 查询结果
  SELECT * FROM temp_data;

  -- 删除临时表
  DROP TABLE temp_data;
END;
/

这个存储过程创建了一个临时表 `temp_data` 来保存查询结果，并将每个查询的结果插入到临时表中。最后，通过查询 `temp_data` 表来获取结果。

请注意，根据你的实际需求和数据库结构，你可能需要修改表和列的定义，以及查询的逻辑。确保在执行存储过程之前，已经创建了所需的表和索引。

SELECT K.LOG_TIME ,COUNT(K.USER_ID) AS 当天的新增用户数 ,COUNT(B.USER_ID) AS 1 日留存率 ,COUNT(C.USER_ID) AS 7 日留存率 ,COUNT(D.USER_ID) AS 30 日留存率 FROM ( SELECT A.USER_ID ,A.LOG_TIME FROM TAB1 A GROUP BY A.USER_ID,A.LOG_TIME ) K LEFT JOIN (SELECT A.USER_ID ,A.LOG_TIME FROM TAB1 A GROUP BY A.USER_ID,A.LOG_TIME ) B ON B.USER_ID = K.USER_ID AND B.LOG_TIME = K.LOG_TIME + 1 LEFT JOIN (SELECT A.USER_ID ,A.LOG_TIME FROM TAB1 A GROUP BY A.USER_ID,A.LOG_TIME) C ON C.USER_ID = K.USER_ID AND C.LOG_TIME = K.LOG_TIME + 6 LEFT JOIN (SELECT A.USER_ID ,A.LOG_TIME FROM TAB1 A GROUP BY A.USER_ID,A.LOG_TIME ) D ON D.USER_ID = K.USER_ID AND D.LOG_TIME = K.LOG_TIME + 29 WHERE K.LOG_TIME = DATE'2019-05-01' GROUP BY K.LOG_TIME ORDER BY K.LOG_TIME ; 这句sql是什么意思

这个 SQL 查询语句用于计算某一天的新增用户数和该天新增用户在接下来的 1、7、30 天内的留存率。具体的 SQL 语句如下：

SELECT 
    K.LOG_TIME,
    COUNT(K.USER_ID) AS 当天的新增用户数,
    COUNT(B.USER_ID) AS 1 日留存率,
    COUNT(C.USER_ID) AS 7 日留存率,
    COUNT(D.USER_ID) AS 30 日留存率
FROM 
    (SELECT 
        A.USER_ID,
        A.LOG_TIME
    FROM 
        TAB1 A
    GROUP BY 
        A.USER_ID, A.LOG_TIME) K
    LEFT JOIN 
        (SELECT 
            A.USER_ID,
            A.LOG_TIME
        FROM 
            TAB1 A
        GROUP BY 
            A.USER_ID, A.LOG_TIME) B
        ON B.USER_ID = K.USER_ID 
        AND B.LOG_TIME = K.LOG_TIME + 1
    LEFT JOIN 
        (SELECT 
            A.USER_ID,
            A.LOG_TIME
        FROM 
            TAB1 A
        GROUP BY 
            A.USER_ID, A.LOG_TIME) C
        ON C.USER_ID = K.USER_ID 
        AND C.LOG_TIME = K.LOG_TIME + 6
    LEFT JOIN 
        (SELECT 
            A.USER_ID,
            A.LOG_TIME
        FROM 
            TAB1 A
        GROUP BY 
            A.USER_ID, A.LOG_TIME) D
        ON D.USER_ID = K.USER_ID 
        AND D.LOG_TIME = K.LOG_TIME + 29
WHERE 
    K.LOG_TIME = DATE'2019-05-01'
GROUP BY 
    K.LOG_TIME
ORDER BY 
    K.LOG_TIME;

这个查询语句使用了多个 SQL 关键字和函数，下面对每个部分进行解释：

- `SELECT`：用于指定需要查询的列，可以使用别名来改变列名。
- `COUNT`：用于计算每个留存时间段内的用户数。
- `FROM`：用于指定查询的表以及表之间的连接方式。
- `LEFT JOIN`：用于指定表之间的连接方式，左连接会返回左表中的所有记录和右表中匹配的记录。
- `GROUP BY`：用于指定分组的列，需要与聚合函数一起使用。
- `ORDER BY`：用于指定查询结果的排序方式。

这个查询语句中使用了多个表之间的连接，并且使用了 LEFT JOIN 进行左连接，这个语法在 SQL 中也是支持的。同时，需要注意在 Hive 中分组查询和聚合函数的使用方式与传统的 SQL 有些不同，需要仔细阅读 Hive 的文档和教程。