MySQL query to transform table

Posted on 2013-11-06
Last Modified: 2013-11-06

I need a mysql query to transform Table1 into Table2.

Thank you,

Name    |     Date        |   Hours    
John    |    2013-10-09  |      8
Mark    |    2013-10-10  |     7.20
Andy    |    2013-10-10 |    9.10
Mark    |    2013-10-09  |     8.30
Mark    |    2013-10-11 |       8
 Name   |2013-10-09| 2013-10-10 | 2013-10-11
   John   |       8       |      -            |       -
   Mark   |      8.30   |     7.20        |      8
 Andy    |        -       |     9.10        |      -
Question by:Qw M
  • 2
  • 2
LVL 22

Expert Comment

ID: 39627276
thats using a Pivot Table

I credit Jimhorn for this  link 

good examples here
LVL 11

Expert Comment

ID: 39627318
Q1: Would Table2's date columns be limited (like always from day 1 to 31 of a day) or should it be dynamic based on the data (in other words show a column for every date whether there are 1 or 100)

Q2: What about dates not in range? If Table 1 has data for 2013-10-01, 2013-10-02 and 2013-10-04 but not 2013-10-03, should it show 2013-10-03 with a 0 count?

Author Comment

by:Qw M
ID: 39627334

Q1:  date columns will be limited (0-31).
Q2: should show the character "-".

Thank you!
LVL 11

Accepted Solution

Louis01 earned 500 total points
ID: 39627351
This should give you a good start:
  SUM(IF(DAY([Date]) = 1, [Hours], NULL)) AS '01',
  SUM(IF(DAY([Date]) = 2, [Hours], NULL)) AS '02',
  SUM(IF(DAY([Date]) = 31, [Hours], NULL)) AS '31',
  [Date] between '2013-10-01' and '2013-10-31'

Open in new window

The output in the date columns would be numeric. You can change it to VARCHAR and check for NULL and show "-" but it is often easier to show "-" for null in whatever application output the values.

Author Comment

by:Qw M
ID: 39627381
Thank you Louis01!

Featured Post

3 Use Cases for Connected Systems

Our Dev teams are like yours. They’re continually cranking out code for new features/bugs fixes, testing, deploying, testing some more, responding to production monitoring events and more. It’s complex. So, we thought you’d like to see what’s working for us.

Question has a verified solution.

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

Suggested Solutions

Title # Comments Views Activity
Oracle Stored Procedure for User Account data 2 28
SQL Pivot Rows To Columns 10 54
SQL View Syntax case etc 5 35
MS SQL 2008 Divide by zero error encountered. Error 3 36
In database programming, custom sort order seems to be necessary quite often, at least in my experience and time here at EE. Within the realm of custom sorting is the sorting of numbers and text independently (i.e., treating the numbers as number…
PL/SQL can be a very powerful tool for working directly with database tables. Being able to loop will allow you to perform more complex operations, but can be a little tricky to write correctly. This article will provide examples of basic loops alon…
This video shows how to use Hyena, from SystemTools Software, to bulk import 100 user accounts from an external text file. View in 1080p for best video quality.
Although Jacob Bernoulli (1654-1705) has been credited as the creator of "Binomial Distribution Table", Gottfried Leibniz (1646-1716) did his dissertation on the subject in 1666; Leibniz you may recall is the co-inventor of "Calculus" and beat Isaac…

809 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