Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <blockquote> <p>This is a post about a super quick-and-dirty way to create a histogram in MySQL for numeric values.</p> <p>There are multiple other ways to create histograms that are better and more flexible, using CASE statements and other types of complex logic. This method wins me over time and time again since it's just so easy to modify for each use case, and so short and concise. This is how you do it:</p> <pre><code>SELECT ROUND(numeric_value, -2) AS bucket, COUNT(*) AS COUNT, RPAD('', LN(COUNT(*)), '*') AS bar FROM my_table GROUP BY bucket; </code></pre> <p>Just change numeric_value to whatever your column is, change the rounding increment, and that's it. I've made the bars to be in logarithmic scale, so that they don't grow too much when you have large values.</p> <p>numeric_value should be offset in the ROUNDing operation, based on the rounding increment, in order to ensure the first bucket contains as many elements as the following buckets. </p> <p>e.g. with ROUND(numeric_value,-1), numeric_value in range [0,4] (5 elements) will be placed in first bucket, while [5,14] (10 elements) in second, [15,24] in third, unless numeric_value is offset appropriately via ROUND(numeric_value - 5, -1).</p> <p>This is an example of such query on some random data that looks pretty sweet. Good enough for a quick evaluation of the data.</p> <pre><code>+--------+----------+-----------------+ | bucket | count | bar | +--------+----------+-----------------+ | -500 | 1 | | | -400 | 2 | * | | -300 | 2 | * | | -200 | 9 | ** | | -100 | 52 | **** | | 0 | 5310766 | *************** | | 100 | 20779 | ********** | | 200 | 1865 | ******** | | 300 | 527 | ****** | | 400 | 170 | ***** | | 500 | 79 | **** | | 600 | 63 | **** | | 700 | 35 | **** | | 800 | 14 | *** | | 900 | 15 | *** | | 1000 | 6 | ** | | 1100 | 7 | ** | | 1200 | 8 | ** | | 1300 | 5 | ** | | 1400 | 2 | * | | 1500 | 4 | * | +--------+----------+-----------------+ </code></pre> <p>Some notes: Ranges that have no match will not appear in the count - you will not have a zero in the count column. Also, I'm using the ROUND function here. You can just as easily replace it with TRUNCATE if you feel it makes more sense to you.</p> </blockquote> <p>I found it here <a href="http://blog.shlomoid.com/2011/08/how-to-quickly-create-histogram-in.html">http://blog.shlomoid.com/2011/08/how-to-quickly-create-histogram-in.html</a></p>
    singulars
    1. This table or related slice is empty.
    1. POGetting data for histogram plot
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USCary Reams
    1. USJaro
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. POGetting data for histogram plot
      singulars
      1. PTQuestion
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. This table or related slice is empty.
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload