Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>You could create the values as instances of the "class":</p> <pre><code>function TestEnum(value) { this._value = value; } TestEnum.prototype.valueOf = function() { return this._value; } TestEnum.prototype.toString = function() { return 'TestEnum_' + this._value; } TestEnum.VALUE_0 = new TestEnum(0); TestEnum.VALUE_1 = new TestEnum(1); </code></pre> <p>The following would work then:</p> <pre><code>TestEnum.VALUE_0 instanceof TestEnum </code></pre> <p>But it also means you'd have to explicitly access the numerical value of one value with <code>.valueOf</code>. In some cases JS will do this automatically for you (like in <code>5 + TestEnum.VALUE_1</code>). Overriding <code>toString</code> so that you can use a value as property might also be necessary.</p> <p>It really depends on your use case whether this is a viable solution.</p> <hr> <p>Alternatively, if just want to test whether a value is part of the enum, you can have an additional property which holds all possible values:</p> <pre><code>TestEnum.values = {0: true, 1: true, ...}; </code></pre> <p>And then test it with</p> <pre><code>value in TestEnum.values // or more reliable (fails for inherited `Object` properties) TestEnum.values.hasOwnProperty(value); </code></pre> <p>You could even automate this:</p> <pre><code>function collectValues(obj) { var values = {}; // or Object.create(null) if available for (var prop in obj) { if (obj.hasOwnProperty(prop)) { values[obj[prop]] = true; } } return values; } TestEnum.values = collectValues(TestEnum); </code></pre> <p>This will only reliably work for primitive values though and won't distinguish between the string <code>"1"</code> and the number <code>1</code>.</p>
    singulars
    1. This table or related slice is empty.
    1. POVariable is instance of Enum
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USFelix Kling
    1. USFelix Kling
    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. 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. COInteresting. Really, what I'm trying to do here is restrict the value that can be passed into that function to a certain subset of valid values. I could just go the simple route of saying `if value == 1 || 2 || 3` etc, but I thought it would be a little more maintainable and make the code easier to read if I used a custom type rather than just throwing meaningless integers around.
      singulars
      1. PO
      1. USMansfield
    2. COWell, you could also just have a map with valid values: `TestEnum.values = {0: true, 1: true, ...}` and test a value with `value in TestEnum.values`.
      singulars
      1. PO
      1. USFelix Kling
 

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