SQL for normalizing repeating groups in a text file

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SQL for normalizing repeating groups in a text file

marerose888

Old Hand

Points: 317
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August 22, 2010 at 10:19 am

#225052

I would like to know how to create the SQL for normalizing a repeating group text file. An example of the data below.
ProductNbr, Date, Red, Blue, Green, Yellow
A102 02-01-2010, 10 15 0 5
Needed Result of data inserted into a table.
ProductNbr, Date, Color Units
A102 02-01-2010 Red 10
A102 02-01-2010 Blue 15
A102 02-01-2010 Green 0
A102 02-01-2010 Red 10
A102 02-01-2010 Yellow 5

Viewing 15 posts - 1 through 15 (of 18 total)

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steve-893342 SSCarpal Tunnel Points: 4439 More actions · Answer 1

Using this approach, you will need to construct a format file based on your text file. This method sets up a cte to read your text file with OPENROWSET BULK and then normalizes the data using CROSS APPLY.

WITH cte AS

(

SELECT * FROM OPENROWSET (BULK 'C:\Sample.txt', FORMATFILE = 'C:\SampleFormat.fmt', FIRSTROW = 2) AS X

)

SELECT cte.ProductNbr, cte.Date, Z.Color, Z.Units

FROM cte

CROSS APPLY

(

SELECT 'Red', Red UNION ALL

SELECT 'Blue', Blue UNION ALL

SELECT 'Green', Green UNION ALL

SELECT 'Yellow', Yellow

) AS Z (Color, Units)

Jeff Moden SSC Guru Points: 1004340 More actions · Answer 2

You could also use UNPIVOT once you have the data in a staging table.

--Jeff Moden

RBAR is pronounced "ree-bar" and is a "Modenism" for Row-By-Agonizing-Row.
First step towards the paradigm shift of writing Set Based code:
________Stop thinking about what you want to do to a ROW... think, instead, of what you want to do to a COLUMN.

Change is inevitable... Change for the better is not.

Helpful Links:
How to post code problems
How to Post Performance Problems
Create a Tally Function (fnTally)

marerose888 Old Hand Points: 317 More actions · Answer 3

I have never heard of or used a UNPIVOT function. Can you please detail how it is used in a SQL statement.

Thanks

Mare

Steve Jones - SSC Editor SSC Guru Points: 736212 More actions · Answer 4

Steve Jones - SSC Editor

SSC Guru

Points: 736212

August 23, 2010 at 9:26 am

#1210526

http://technet.microsoft.com/en-us/library/ms177410.aspx

marerose888 Old Hand Points: 317 More actions · Answer 5

Thanks for your info...but if I have the data in a table, (which would be the initial process,) would I only have to use the following part of the statement:

SELECT ProdColortbl.ProductNbr, ProdColortbl.Date, Z.Color, Z.Units

FROM ProdColortbl

CROSS APPLY

(

SELECT 'Red', Red UNION ALL

SELECT 'Blue', Blue UNION ALL

SELECT 'Green', Green UNION ALL

SELECT 'Yellow', Yellow

) AS Z (Color, Units)

Post #973090

steve-893342 SSCarpal Tunnel Points: 4439 More actions · Answer 6

Try it. Does it give you the output you are looking for?

marerose888 Old Hand Points: 317 More actions · Answer 7

I created a table in Access (don't have access to SQL server today) with the repeating fields of colors, then ran sql in my ETL tool and I got this error.

1. ERROR

DS-DBMS-E400: UDA driver reported the following on connection 'DS_Sales':

UDA-SQL-0043 The underlying database detected an error during processing the SQL request.

[Microsoft][ODBC Microsoft Access Driver] Syntax error in FROM clause.

SELECT

Products.ProductNbr, Products.Date, Z.Color, Z.Units

FROM Products

CROSS APPLY

(

SELECT 'Red', Red UNION ALL

SELECT 'Blue', Blue UNION ALL

SELECT 'Green', Green UNION ALL

SELECT 'Yellow', Yellow

) AS Z (Color, Units)

Jeff Moden SSC Guru Points: 1004340 More actions · Answer 8

marerose888 (8/23/2010)
I created a table in Access (don't have access to SQL server today) with the repeating fields of colors, then ran sql in my ETL tool and I got this error.
1. ERROR
DS-DBMS-E400: UDA driver reported the following on connection 'DS_Sales':
UDA-SQL-0043 The underlying database detected an error during processing the SQL request.
[Microsoft][ODBC Microsoft Access Driver] Syntax error in FROM clause.
SELECT
Products.ProductNbr, Products.Date, Z.Color, Z.Units
FROM Products
CROSS APPLY
(
SELECT 'Red', Red UNION ALL
SELECT 'Blue', Blue UNION ALL
SELECT 'Green', Green UNION ALL
SELECT 'Yellow', Yellow
) AS Z (Color, Units)

I'm pretty sure that ACCESS doesn't have a CROSS APPLY in it.

--Jeff Moden

RBAR is pronounced "ree-bar" and is a "Modenism" for Row-By-Agonizing-Row.
First step towards the paradigm shift of writing Set Based code:
________Stop thinking about what you want to do to a ROW... think, instead, of what you want to do to a COLUMN.

Change is inevitable... Change for the better is not.

Helpful Links:
How to post code problems
How to Post Performance Problems
Create a Tally Function (fnTally)

steve-893342 SSCarpal Tunnel Points: 4439 More actions · Answer 9

If you are restricted to the Access environment, you could use a SQL Pass-Through Query

pietlinden SSC Guru Points: 63503 More actions · Answer 10

If you're doing this in Access, just use the crosstab query wizard... 🙂

marerose888 Old Hand Points: 317 More actions · Answer 11

Ok tried that...didn't work. you can't flip the repeating group fields in to one field...unless I am missing something. Here is the table data with the repeating groups. You want to pivot the colors and metrics in the "color" field.

ProductNbrDateColorRedBlueGreenYellow

1234 2/10/2010152030

1245 3/15/2010210314

1645 7/20/20105151418

1704 6/15/20101215

steve-893342 SSCarpal Tunnel Points: 4439 More actions · Answer 12

OK so here it is, an ACCESS UNPIVOT query. You will need to create a table called Tally with a single field N, Data Type Number. Simply enter into this Tally table the values 1, 2, 3, 4. Then try the query below.

SELECT ProductNbr, [Date],

iif(N = 1, 'Red', iif(N = 2, 'Blue', iif(N = 3, 'Green', iif(N = 4, 'Yellow', '')))) AS Color,

iif(N = 1, Red, iif(N = 2, Blue, iif(N = 3, Green, iif(N = 4, Yellow, '')))) AS Units

FROM Products, Tally

ORDER BY ProductNbr;

steve-893342 SSCarpal Tunnel Points: 4439 More actions · Answer 13

BTW did you try running the below as a SQL PASS-THROUGH query as I suggested previously? That should work fine too;-)

SELECT ProdColortbl.ProductNbr, ProdColortbl.Date, Z.Color, Z.Units

FROM ProdColortbl

CROSS APPLY

(

SELECT 'Red', Red UNION ALL

SELECT 'Blue', Blue UNION ALL

SELECT 'Green', Green UNION ALL

SELECT 'Yellow', Yellow

) AS Z (Color, Units)

marerose888 Old Hand Points: 317 More actions · Answer 14

Wow it worked...although I know an initial process would have to be set up first to build the "Tally" table and populate it with all the repeating groups. Now that could be interesting...to do that and not know if the repeating groups are static or not. Anyway, I will try to figure that out....unless of course you know how.

Anyway, now to further expose my ignorance of this function, how in the second set of iif statements ( iif(N = 1, Red, iif(N = 2, Blue, iif(N = 3, Green, iif(N = 4, Yellow, '')))) AS Units ( does the logic recognize that if the N = 1 and color is Red that the Units grab the units and the column color be populated with the right amount. I will understand if this is hard to describe because I can't see it visually;. But I am determined to learn all I can about this. I will be doing a lot of pivoting ETL for a client that is having to deal with flat files that don't adhere to the 3rd normal form.

I have don't this will a very sophisticated ETL tool but I want to learn it from the basic code level. But unfortunately I am only able to use MS Access.

Thanks a bunch.

Mare