Question

我有2张桌子

PREVI_INFO

╔══════════╦══════════════╦═════════════╦══════════════════╦════════════╗
║ previ_id ║ code_station ║ code_modele ║    date_previ    ║ type_previ ║
╠══════════╬══════════════╬═════════════╬══════════════════╬════════════╣
║   501201 ║         2952 ║          48 ║ 29/01/2017 15:00 ║ AUTO       ║
║   501156 ║         2952 ║          48 ║ 30/01/2017 07:00 ║ AUTO       ║
╚══════════╩══════════════╩═════════════╩══════════════════╩════════════╝

PREVI_VAL

╔══════════╦═══════════════╦═════════════════════╦══════════════╗
║ previ_id ║ code_scenario ║        temps        ║ valeur_debit ║
╠══════════╬═══════════════╬═════════════════════╬══════════════╣
║   501201 ║            -1 ║ 30/01/2017 10:00:00 ║ 2,024        ║
║   501201 ║            -1 ║ 30/01/2017 13:00:00 ║ 2,215        ║
║   501201 ║             0 ║ 30/01/2017 10:00:00 ║ 1,456        ║
║   501201 ║             0 ║ 30/01/2017 13:00:00 ║ 1.687        ║
╚══════════╩═══════════════╩═════════════════════╩══════════════╝

QUERY

对于给定的 code_model ，我需要获取最近的 previ_val 以获取 code_scenario

的列表

我现在拥有的：

SELECT *
FROM (
  SELECT previ_id, type_previ
  FROM (
    SELECT previ_id, type_previ
    FROM PREVI.previ_info
    WHERE code_modele = '48'
    ORDER BY date_previ DESC
  ) pi
  WHERE ROWNUM < 2
) pi
JOIN PREVI.previ_val pv
ON pv.previ_id = pi.previ_id

给了我

╔══════════╦════════════╦═══════════════╦═════════════════════╦════════════════════╗
║ previ_id ║ type_previ ║ code_scenario ║        temps        ║    valeur_debit    ║
╠══════════╬════════════╬═══════════════╬═════════════════════╬════════════════════╣
║   501201 ║ AUTO       ║ -1            ║ 30/01/2017 10:00:00 ║ 2,027503327181698  ║
║   501201 ║ AUTO       ║ -1            ║ 30/01/2017 13:00:00 ║ 2,289291759560228  ║
║   501201 ║ AUTO       ║ -1            ║ 30/01/2017 16:00:00 ║ 2,488605471829943  ║
║   501201 ║ AUTO       ║ -1            ║ 30/01/2017 19:00:00 ║ 2,5768532759013274 ║
║   501201 ║ AUTO       ║ -1            ║ 30/01/2017 22:00:00 ║ 2,5567552515698297 ║
║   501201 ║ AUTO       ║ -1            ║ 31/01/2017 01:00:00 ║ 2,4847510721331894 ║
║   501201 ║ AUTO       ║ -1            ║ 31/01/2017 04:00:00 ║ 2,371160558216584  ║
║   501201 ║ AUTO       ║ 0             ║ 30/01/2017 10:00:00 ║ 2,027503327181698  ║
║   501201 ║ AUTO       ║ 0             ║ 30/01/2017 13:00:00 ║ 2,281620351009415  ║
║   501201 ║ AUTO       ║ 0             ║ 30/01/2017 16:00:00 ║ 2,4679642018714993 ║
║   501201 ║ AUTO       ║ 0             ║ 30/01/2017 19:00:00 ║ 2,5426531265028185 ║
║   501201 ║ AUTO       ║ 0             ║ 30/01/2017 22:00:00 ║ 2,510706411016839  ║
║   501201 ║ AUTO       ║ 0             ║ 31/01/2017 01:00:00 ║ 2,4287719529773804 ║
║   501201 ║ AUTO       ║ 0             ║ 31/01/2017 04:00:00 ║ 2,308307979316664  ║
║   501201 ║ AUTO       ║ 0,25          ║ 30/01/2017 10:00:00 ║ 2,027503327181698  ║
║   501201 ║ AUTO       ║ 0,25          ║ 30/01/2017 13:00:00 ║ 2,2950103323648503 ║
║   501201 ║ AUTO       ║ 0,25          ║ 30/01/2017 16:00:00 ║ 2,506610245355028  ║
║   501201 ║ AUTO       ║ 0,25          ║ 30/01/2017 19:00:00 ║ 2,6144186413564663 ║
║   501201 ║ AUTO       ║ 0,25          ║ 30/01/2017 22:00:00 ║ 2,63992592676027   ║
║   501201 ║ AUTO       ║ 0,25          ║ 31/01/2017 01:00:00 ║ 2,6660032204209982 ║
║   501201 ║ AUTO       ║ 0,25          ║ 31/01/2017 04:00:00 ║ 2,689414559791597  ║
╚══════════╩════════════╩═══════════════╩═════════════════════╩════════════════════╝

期望的结果

╔══════════╦════════════╦═══════════════╦═════════════════════╦════════════════════╗
║ previ_id ║ type_previ ║ code_scenario ║        temps        ║    valeur_debit    ║
╠══════════╬════════════╬═══════════════╬═════════════════════╬════════════════════╣
║   501201 ║ AUTO       ║ -1            ║ 30/01/2017 13:00:00 ║ 2,289291759560228  ║
║   501201 ║ AUTO       ║ 0             ║ 30/01/2017 13:00:00 ║ 2,281620351009415  ║
╚══════════╩════════════╩═══════════════╩═════════════════════╩════════════════════╝

这给了我下一个日期的行。如果是30/01/2017 12:45，我需要30/01/2017 13:00:00而不是10:00:00的排。代码来自列表。目前只有0和-1。

如何改进查询以使其有效？

Answer 1

对于给定的code_model，我需要获取最近的previ_val以获取code_scenario列表

您可以使用ROW_NUMBER分析功能。目前还不清楚你是如何对数据进行分区的，但是这样的事情应该有效：

SELECT *
FROM   (
  SELECT i.*,
         v.*,
         ROW_NUMBER() OVER ( PARTITION BY i.previ_id, v.code_scenario
                             ORDER BY ABS( i.date_previ - v.temps ) ) AS rn
  FROM   ( SELECT *
           FROM   ( SELECT *
                    FROM   PREVI_INFO
                    WHERE  i.code_modele = 48
                    ORDER BY date_previ DESC )
           WHERE ROWNUM = 1
         ) i
         INNER JOIN PREVI_VAL v
         ON ( i.previ_id = v.previ_id )
)
WHERE rn = 1;

<强>更新：

我需要获得与现在相比较的下一个日期。

这将加入temps值在SYSDATE之后的表格，然后按时间顺序获取第一个：

SELECT *
FROM   (
  SELECT i.*,
         v.*,
         ROW_NUMBER() OVER ( PARTITION BY i.previ_id, v.code_scenario
                             ORDER BY v.temps ) AS rn
  FROM   ( SELECT *
           FROM   ( SELECT *
                    FROM   PREVI_INFO
                    WHERE  i.code_modele = 48
                    ORDER BY date_previ DESC )
           WHERE ROWNUM = 1
         ) i
         INNER JOIN PREVI_VAL v
         ON (   i.previ_id = v.previ_id 
            AND v.temps >= SYSDATE )
)
WHERE rn = 1;

每个代码

1 个答案: