Databases
StackOverflow2013
Postsdbo
POSchema for storing "binary" values, such as Male/Female, in a database
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POSchema for storing "binary" values, such as Male/Female, in a database
    primarykey
    data
    text
    <h2>Intro</h2> <p>I am trying to decide how best to set up my database schema for a (Rails) model. I have a model related to money which indicates whether the value is an income (positive cash value) or an expense (negative cash value).</p> <p>I would like separate column(s) to indicate whether it is an income or an expense, rather than relying on whether the value stored is positive or negative.</p> <hr> <h2>Question:</h2> <p>How would you store these values, and why?</p> <ul> <li>Have a single column, say <code>Income</code>, and store <code>1</code> if it's an income, <code>0</code> if it's an expense, <code>null</code> if not known.</li> <li>Have two columns, <code>Income</code> and <code>Expense</code>, setting their values to <code>1</code> or <code>0</code> as appropriate. </li> <li>Something else?</li> </ul> <p>I figure the question is similar to storing a person's gender in a database (ignoring aliens/transgender/etc) hence my title.</p> <hr> <h2>My thoughts so far</h2> <ul> <li>Lookup might be easier with a single column, but there is a risk of mistaking <code>0</code> (<code>false</code>, expense) for <code>null</code> (unknown).</li> <li>Having seperate columns might be more difficult to maintain (what happens if we end up with a <code>1</code> in both columns?</li> </ul> <p>Maybe it's not that big a deal which way I go, but it would be great to have any concerns/thoughts raised before I get too far down the line and have to change my code-base because I missed something that should have been obvious!</p> <p>Thanks, Philip</p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. This table or related slice is empty.
    1. USlatentflip
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    3. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POSchema for storing "binary" values, such as Male/Female, in a database
      1. This table or related slice is empty.
      1. VTUpMod
    1. COYou haven't even developed the tables yet, and you are already expecting them to be filled with bad data (0s for null, and 1 for both Income and Expense columns)? How do you hope to have a working system in such an environment?
      singulars
      1. POSchema for storing "binary" values, such as Male/Female, in a database
      1. USJeffrey L Whitledge
    2. COWhat on earth would you do with an "unknown" transaction type?
      singulars
      1. POSchema for storing "binary" values, such as Male/Female, in a database
      1. USkurosch
    3. CO@Jeffrey - Well I would certainly hope that neither of those cases actually happened, I was just trying to think about possible advantages/disadvantages of either schema.
      singulars
      1. POSchema for storing "binary" values, such as Male/Female, in a database
      1. USlatentflip
 

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