Solved

Query syntax - PIVOT?

Posted on 2013-11-19
8
214 Views
Last Modified: 2013-11-19
Hello,

I have a tabled defined as:

CREATE TABLE [dbo].[DocumentData](
	[doc_id] [int] NOT NULL,
	[ddt_FieldName] [nvarchar](20) NULL,
	[ddt_FieldValue] [nvarchar](100) NULL,
	[ddt_Changed] [bit] NULL,
	[ddt_ChangedUserId] [int] NULL,
	[ddt_ChangedDateTime] [datetime] NULL,
	[id] [int] IDENTITY(1,1) NOT NULL
) ON [PRIMARY]

Open in new window


It contains data collected from a document - identified by doc_id.  

For each document there are many rows where each row is a field name and a field value.

If i know that my document has ddt_FieldNames of A, B, C and D how would i write an sql statement to produce all the data in columns for document with doc_id 6?

I am looking for output like:

doc_id      A      B      C      D
6               10    66   12     13

where A, B, C, and D have respective ddt_FieldValues  of 10, 66, 12 , 13
0
Comment
Question by:soozh
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 4
  • 3
8 Comments
 
LVL 11

Expert Comment

by:Louis01
ID: 39659016
Q1: I suppose the columns (A-D) comes from ddt_FieldNames?
Q2: Would it always be A, B, C & D? Can there be more names?
Q3: Do you need to sum ddt_FieldValues?
0
 

Author Comment

by:soozh
ID: 39659032
Q1: I suppose the columns (A-D) comes from ddt_FieldNames?
Yes


Q2: Would it always be A, B, C & D? Can there be more names?
No

Q3: Do you need to sum ddt_FieldValues?
No


I just need a row of data for each document.

Thanks
0
 
LVL 11

Expert Comment

by:Louis01
ID: 39659034
Your response of No to Q2:
No, there can be more names or No, it would always be ABC&D?

Q4: What to do when no row is found for ddt_FieldNames?
Q5: What to do when there us more than one of the same value in ddt_FieldNames?
0
RHCE - Red Hat OpenStack Prep Course

This course will provide in-depth training so that students who currently hold the EX200 & EX210 certifications can sit for the EX310 exam. Students will learn how to deploy & manage a full Red Hat environment with Ceph block storage, & integrate Ceph into other OpenStack service

 

Author Comment

by:soozh
ID: 39659041
It should Always be A B C and D

Q4: return null as the value

Q5:  There should only be one row in the table for each document so i expect that i would have to add the document number to the final Query.
0
 
LVL 11

Expert Comment

by:Louis01
ID: 39659050
The simplest way to achieve this would be:
select [doc_id]
     , CASE [ddt_FieldName] WHEN 'A' THEN [ddt_FieldValue] ELSE 0 END as 'A'
     , CASE [ddt_FieldName] WHEN 'B' THEN [ddt_FieldValue] ELSE 0 END as 'B'
     , CASE [ddt_FieldName] WHEN 'C' THEN [ddt_FieldValue] ELSE 0 END as 'C'
     , CASE [ddt_FieldName] WHEN 'D' THEN [ddt_FieldValue] ELSE 0 END as 'D'
  from DocumentData

Open in new window

0
 
LVL 11

Accepted Solution

by:
Louis01 earned 500 total points
ID: 39659057
You could use the PIVOT function as follows:
select [doc_id], [A], [B], [C], [D]
  from (select doc_id, ddt_FieldName, ddt_FieldValue
          from DocumentData) as pt_src
PIVOT (MAX(ddt_FieldValue) FOR ddt_FieldName IN ([A], [B], [C], [D])) as pt

Open in new window

0
 
LVL 49

Expert Comment

by:PortletPaul
ID: 39659080
No points please.

Louis01, you forgot the max( ... ) and group by
select [doc_id]
     , MAX ( CASE [ddt_FieldName] WHEN 'A' THEN [ddt_FieldValue] ELSE 0 END ) as 'A'
     , MAX ( CASE [ddt_FieldName] WHEN 'B' THEN [ddt_FieldValue] ELSE 0 END ) as 'B'
     , MAX ( CASE [ddt_FieldName] WHEN 'C' THEN [ddt_FieldValue] ELSE 0 END ) as 'C'
     , MAX ( CASE [ddt_FieldName] WHEN 'D' THEN [ddt_FieldValue] ELSE 0 END ) as 'D'
  from DocumentData
group by [doc_id]

Open in new window

I did exactly the same thing myself recently :)
0
 

Author Closing Comment

by:soozh
ID: 39659082
The pivot worked.  The other solution created many rows.  Thanks.
0

Featured Post

Free Tool: Site Down Detector

Helpful to verify reports of your own downtime, or to double check a downed website you are trying to access.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

In this article I will describe the Copy Database Wizard method as one possible migration process and I will add the extra tasks needed for an upgrade when and where is applied so it will cover all.
This article explains how to reset the password of the sa account on a Microsoft SQL Server.  The steps in this article work in SQL 2005, 2008, 2008 R2, 2012, 2014 and 2016.
Michael from AdRem Software outlines event notifications and Automatic Corrective Actions in network monitoring. Automatic Corrective Actions are scripts, which can automatically run upon discovery of a certain undesirable condition in your network.…
Michael from AdRem Software explains how to view the most utilized and worst performing nodes in your network, by accessing the Top Charts view in NetCrunch network monitor (https://www.adremsoft.com/). Top Charts is a view in which you can set seve…

623 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question