Add a Twig function to create yii\db\Expression objects

[carlcs]

Sometimes it’s not possible to pass a db expression as a string, becaus Yii escapes it and generates invalid SQL. yiisoft/yii2#553

Example use of the function:

{% set ids = [1639, 2079] %}

{% set orderByParam = ids ?
    dbExpression('FIELD(elements.id, ' ~ ids|reverse|join(', ') ~ ') desc, title asc') :
    'title asc' %}

{% set query = craft.entries
    .limit(50)
    .orderBy(orderByParam) %}

[brandonkelly]

I like this. Can you rename the function to expression() instead of dbExpression() though?

[brandonkelly]

(Worth noting that your particular example could also be achieved using the fixedOrder param though.)

[carlcs]

@brandonkelly fixedOrder only works when using it in combination with ids() though. In this example the ids variable is an array of element IDs for entries that should show up first, but there are more entries returned.

[carlcs]

{% set ids = blog.featuredBlogEntries.ids() %}

This makes the example clearer.

[brandonkelly]

Ah gotcha, thanks for clarification! Though I realize expressions could be used for a variety of things so wouldn't have declined the PR anyway :)