Solved

How to generate list of unique values in csv column?

Posted on 2014-01-18
2
554 Views
Last Modified: 2014-01-19
I have to work with a non-normalized table in MYSQL which I do not have the ability to alter.

The table has a column (col1) which has comma separated values.

I need to generate a list of distinct values within all rows for col1.

Can someone please provide me a query to do that?

col1
------
a,b,c
b,a,g
g,h

Desired result:
a
b
c
g
h
0
Comment
Question by:SAbboushi
2 Comments
 
LVL 34

Accepted Solution

by:
Dan Craciun earned 500 total points
ID: 39791863
First of all, MySQL is not really the tool for this. You can use the language of your choice and simply do a split, explode, whatever.

However, if you insist, it can be done :)

First, you would need to define a split function. Here's the code, copied from here: http://injustfiveminutes.com/2012/10/17/split-function-in-mysql/
CREATE FUNCTION SPLIT_STR(
  x VARCHAR(255),
  delim VARCHAR(12),
  pos INT
)
RETURNS VARCHAR(255)
RETURN REPLACE(SUBSTRING(SUBSTRING_INDEX(x, delim, pos),
       LENGTH(SUBSTRING_INDEX(x, delim, pos -1)) + 1),
       delim, '');

Open in new window


Then, you could use this in your SQL:
CREATE TEMPORARY TABLE temp (val CHAR(255));
INSERT INTO temp(val) VALUES (SELECT SPLIT_STR(col1, ",", 1) FROM your-table), (SELECT SPLIT_STR(col1, ",", 2) FROM your-table), (SELECT SPLIT_STR(col1, ",", 3) FROM your-table);
SELECT DISTINCT val FROM temp;

Open in new window


The code is not tested, but you get the idea. You would need more SPLIT_STR calls if you have more than 3 joined values.

HTH,
Dan
0
 

Author Closing Comment

by:SAbboushi
ID: 39793221
K thanks--
0

Featured Post

Microsoft Certification Exam 74-409

Veeam® is happy to provide the Microsoft community with a study guide prepared by MVP and MCT, Orin Thomas. This guide will take you through each of the exam objectives, helping you to prepare for and pass the examination.

Question has a verified solution.

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

Suggested Solutions

Title # Comments Views Activity
Importing and exporting data Magento 1.x ? 4 84
MySQL ERROR 1045 (28000) 2 78
configure dependency in POM for new database 3 25
How to count in a table in php 22 36
Foreword In the years since this article was written, numerous hacking attacks have targeted password-protected web sites.  The storage of client passwords has become a subject of much discussion, some of it useful and some of it misguided.  Of cou…
Introduction Since I wrote the original article about Handling Date and Time in PHP and MySQL (http://www.experts-exchange.com/articles/201/Handling-Date-and-Time-in-PHP-and-MySQL.html) several years ago, it seemed like now was a good time to updat…
This Micro Tutorial hows how you can integrate  Mac OSX to a Windows Active Directory Domain. Apple has made it easy to allow users to bind their macs to a windows domain with relative ease. The following video show how to bind OSX Mavericks to …
Along with being a a promotional video for my three-day Annielytics Dashboard Seminor, this Micro Tutorial is an intro to Google Analytics API data.

772 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