使用iSeries的SQL将多个行值连接为1行 [英] Concatenate Multiple Row Values into 1 Row, with SQL for iSeries

问题描述

首先，我要感谢肯特·米利根(Kent Milligan)及其他在

First, I need to thank Kent Milligan and his article at http://www.mcpressonline.com/sql/techtip-combining-multiple-row-values-into-a-single-row-with-sql-in-db2-for-i.html for getting me as far in this problem as I have. But now I need to expand on what he has done here.

为避免您不得不阅读他的文章，他解决的问题是将字符串数据从多行连接到结果表中的单行中.例如:

To avoid you having to go to his article, the problem he addressed was concatenating string data from multiple rows into a single row in the resulting table. For example:

桌车:

• 制作模型
• 福特Fusion
• 雪佛兰Tahoe
• 本田奥德赛
• 福特金牛座
• 福特福克斯
• Chevy Malibu

结果:

• 制作模型
• 雪佛兰马里布(Tahoe)
• 福特福克斯，金牛座，融合
• 本田奥德赛

这是通过SQL语句完成的:

This was done with the SQL statement:

WITH numbered_sets(make, model, curr, prev) AS (
   SELECT make, model,
       ROW_NUMBER() OVER (PARTITION BY make ORDER BY model) AS curr,
       ROW_NUMBER() OVER (PARTITION BY make ORDER BY model) -1 AS prev
   FROM inventory)
SELECT make,
       MAX (TRIM(L ',' FROM
             CAST(SYS_CONNECT_BY_PATH(model, ',') AS VARCHAR(256)) ))
FROM numbered_sets
START WITH curr = 1
CONNECT BY make = PRIOR make AND prev = PRIOR curr
GROUP BY make

我能够将其调整到我自己的桌子上，并获得大部分想要的方式.但出于我的目的，我需要在分组中添加其他列.例如:

I was able to adapt that to my own table, and get most of the way where I wanted to get. But for my purposes, I have an additional column I need to include for the grouping. For example:

桌车:

• 制作类型模型
• 福特轿车融合
• 雪佛兰SUV Tahoe
• 本田Minivan Odyssey
• 福特三厢金牛座
• 福特轿车福克斯
• Chevy Sedan Malibu
• 福特SUV Escape
• 福特SUV Explorer
• 雪佛兰Sedan Impala

• Make Type Model
• Ford Sedan Fusion
• Chevy SUV Tahoe
• Honda Minivan Odyssey
• Ford Sedan Taurus
• Ford Sedan Focus
• Chevy Sedan Malibu
• Ford SUV Escape
• Ford SUV Explorer
• Chevy Sedan Impala

对于结果，我一直在寻找:

For the Results, I’d be looking for:

• 制作类型模型
• 雪佛兰Sedan Malibu，黑斑羚
• 雪佛兰SUV Tahoe
• 福特轿车Fusion，金牛座，福克斯
• 福特SUV Escape，Explorer
• 本田Minivan Odyssey

有人对我要添加到原始语句中的所有内容有什么想法，以便能够添加TYPE列，然后相应地添加GROUP?我已经尝试了很多方法，但是我怀疑我需要对CONNECT_BY_PATH语句做些事情，只是不确定是什么.

Does anyone have any thoughts on what all I need to add to the original statement to be able to add the TYPE column, and GROUP on that accordingly? I’ve tried a handful of things, but I suspect I need to do something with the CONNECT_BY_PATH statement, I’m just not sure what.

谢谢

推荐答案

我认为您只需要考虑一下查询的正确点就可以集成类型.

I think you just need to integrate type at the correct points thoughtout the query.

在无法测试的情况下，我认为这已经很接近了；但我可能错过了一些东西...

without being able to test, I think this would be close; but I may have missed something...

WITH numbered_sets(make, type, model, curr, prev) AS (
   SELECT make, type, model,
       ROW_NUMBER() OVER (PARTITION BY make, Type ORDER BY Make, Type, model) AS curr,
       ROW_NUMBER() OVER (PARTITION BY make, type ORDER BY Make, type, model) -1 AS prev
   FROM inventory)
SELECT make, Type
       MAX (TRIM(L ',' FROM
             CAST(SYS_CONNECT_BY_PATH(model, ',') AS VARCHAR(256)) ))
FROM numbered_sets
START WITH curr = 1
CONNECT BY make = PRIOR make AND prev = PRIOR curr and type = prior type
GROUP BY make, type

也许我们需要先更改连接方式，然后再进行连接...尽管我尚不清楚为什么这会有所帮助...

Perhaps we need do change the connect by to do a concat before connect by... though I can't see why this would help yet...

CONNECT BY concat(make,type) = PRIOR concat(make,type) AND prev = PRIOR curr

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