连续日期功能：SAP HANA

Question

我们正试图从表中找到连续的日期

预期输出附在下图中： Expected Output

create column table "PS_CMP_TIME_ANALYTICS"."Temp2" (
"ID"  integer,
"Period"  date);

INSERT INTO "PS_CMP_TIME_ANALYTICS"."Temp2" VALUES (4, '2010-04-03');
INSERT INTO "PS_CMP_TIME_ANALYTICS"."Temp2" VALUES (5, '2010-04-07');
INSERT INTO "PS_CMP_TIME_ANALYTICS"."Temp2" VALUES (2, '2010-04-10');
INSERT INTO "PS_CMP_TIME_ANALYTICS"."Temp2" VALUES (3, '2010-04-15');
INSERT INTO "PS_CMP_TIME_ANALYTICS"."Temp2" VALUES (6, '2010-04-16');
INSERT INTO "PS_CMP_TIME_ANALYTICS"."Temp2" VALUES (7, '2010-04-17');
INSERT INTO "PS_CMP_TIME_ANALYTICS"."Temp2" VALUES (3, '2010-04-22');
INSERT INTO "PS_CMP_TIME_ANALYTICS"."Temp2" VALUES (4, '2010-04-24');
INSERT INTO "PS_CMP_TIME_ANALYTICS"."Temp2" VALUES (7, '2010-04-30');
INSERT INTO "PS_CMP_TIME_ANALYTICS"."Temp2" VALUES (2, '2010-05-01');
INSERT INTO "PS_CMP_TIME_ANALYTICS"."Temp2" VALUES (5, '2010-05-02');
INSERT INTO "PS_CMP_TIME_ANALYTICS"."Temp2" VALUES (3, '2010-05-03');

我们在SAP HANA中尝试的查询和我们得到的输出如下所述：

SELECT MIN("Period") AS BeginRange,
       MAX("Period") AS EndRange
FROM (
SELECT "Period",
    --DATEDIFF(D, ROW_NUMBER() OVER(ORDER BY "Period"), "Period") AS DtRange
cast(ROW_NUMBER() OVER(ORDER BY "Period") as date) as xyz,

    days_between(to_date(cast(ROW_NUMBER() OVER(ORDER BY "Period") as 
Date),'YYYY-MM-DD'), "Period") AS DtRange
FROM "PS_CMP_TIME_ANALYTICS"."Temp2") AS dt
GROUP BY DtRange;

但我们没有按预期获得输出找到附件我们使用SAP HANA SQL应该更改END日期 Our Output

我们如何在SAP HANA SQL中实现

Answer 1

您可以使用SAP HANA中的代码

SELECT MIN("Period") as "Start_Date",MAX("Period") as "End_Date",
(days_between(Min("Period"),Max("Period")) + 1) as "Days"
FROM
(select "Period",add_days("Period" ,- ROW_NUMBER() OVER(ORDER BY "Period"))rn
from "SchemaName"."Temp2")
GROUP BY rn

Answer 2

实际上，您正在查找有序表格列中数据岛的上限，这类似于查找间隙的下限

其他解决方案可以遵循SQLScript，我使用SQL LEAD() function来计算日期字段中的下一个值

with cte as (
    select
    "ID", "Period", LEAD("Period", 1) over (order by "Period") NextDate
    from "Temp2"
)
select "ID", "Period"
from cte
where IFNULL(DAYS_BETWEEN("Period",NextDate),9) > 1

我还使用了SQL CTE expressions，这可能是许多来自ABAP编程经验的HANA开发人员的新语法。 但是我使用它很多，并且在单个SELECT语句中使用多个CTE特别强大。

上述SQLScript查询的输出如下