SQLPlus 透视日期列答案

【问题标题】：SQLPlus Pivot Date ColumnSQLPlus 透视日期列
【发布时间】：2020-09-23 17:06:39
【问题描述】：

我有一个查询，我需要在其中旋转一个包含多个日期的字段。简而言之，manageddate 列需要转为 6 列，其中日期从最新到最旧。

我目前的努力如下

SELECT student_number,
       wheninput,
       whoinput,
       certificatetype,
       MAX(CASE
             WHEN vaccine_name = 'DTP' THEN
              TO_CHAR(administereddate, 'mm/dd/yyyy')
             ELSE
              ''
           END) AS "DTP"
  FROM 
 (
  SELECT TO_CHAR(administeredDate, 'mm/dd/yyyy') dose_date,
         ROW_NUMBER() OVER (PARTITION BY vaccine_name ORDER BY administereddate DESC) dose
    FROM ps.pshealthgrade1) 
   PIVOT(
         LISTAGG(dose_date) WITHIN GROUP (ORDER BY dose_date DESC) 
                                   FOR dose IN (1 DTP_dose1,
                                                2 DTP_dose2,
                                                3 DTP_dose3,
                                                4 DTP_dose4,
                                                5 DTP_dose5,
                                                6 DTP_dose6)
         )
  )
 WHERE vaccine_name = 'DTP'
 GROUP BY student_number,
          wheninput,
          whoinput,
          vaccine_name,
          administereddate,
          certificatetype
 ORDER BY student_number, vaccine_name, administereddate;

【问题讨论】：

标签： sql oracle plsql pivot sqlplus

【解决方案1】：

您需要动态检测可能每天计算的最近六个疫苗日期。为了做到这一点，首先创建这样一个函数;

CREATE OR REPLACE FUNCTION get_vaccine_rs(
                                          i_vcc  ps.pshealthgrade1.vaccine_name%TYPE 
                                         ) RETURN SYS_REFCURSOR IS
  v_recordset SYS_REFCURSOR;
  v_sql       VARCHAR2(32767);
  v_str       VARCHAR2(32767);
BEGIN
  SELECT LISTAGG( ''''||TO_CHAR(administeredDate, 'mm/dd/yyyy')||''' AS "DTP_dose'||rn||'"' , ',' ) 
                 WITHIN GROUP ( ORDER BY rn )
    INTO v_str                 
    FROM ( SELECT *
             FROM
             ( SELECT administeredDate, ROW_NUMBER() OVER (ORDER BY administeredDate DESC) AS rn 
                 FROM ( SELECT DISTINCT administeredDate 
                          FROM ps.pshealthgrade1 
                         WHERE vaccine_name = i_vcc )
             )
            WHERE rn <= 6 );             

  v_sql :=
  'SELECT *
     FROM ps.pshealthgrade1
    PIVOT
    (
     COUNT(*) FOR administeredDate IN ( '|| v_str ||' )
    )
    ';

  OPEN v_recordset FOR v_sql USING i_vcc;
  RETURN v_recordset;
END;
/

然后运行以下代码：

VAR rc REFCURSOR
EXEC :rc := get_vaccine_rs('DTP');
PRINT rc

从 SQL Developer 的命令行查看结果集。

【讨论】：