Laravel Eloquent: JSON comparison - php

Question

I have the following model:
info is a JSON be and the results would look something like this:
{
"cas": "none",
"uom": "6",
"url": "http://www.foobar.com",
"size": "10.00",
"type": "Chemical",
"unit": {
"id": "6",
"name": "gram",
"plural": "grams",
"abbreviation": "g",
"display_order": "6",
"additional_aliases": "gr, gm"
},
"owner": null,
"vendor": "Sigma Aldrich",
"quantity": 8,
"product_name": "Nafion(R), trimethylsilylated",
"catalog_number": "392928-10G",
"ghs_pictograms": [
1
],
"low_level_warning": 3,
"high_level_warning": 7
}
info.quantity tells us how much of this item is left in inventory.
info.low_level_warning / info.high_level_warning is a user entered value where we want to filter by.
So I tried something like this, but it doesn't work:
} else if ($filters['filter'] === 'show_below_min_threshold') {
$query->where(function ($query) {
return $query->where('info->quantity', '<', 'info->low_level_warning');
});
} else if ($filters['filter'] === 'show_above_max_threshold') {
$query->where(function ($query) {
return $query->where('info->quantity', '>', 'info->high_level_warning');
});
}
Any thoughts on what I am doing wrong?

Answer 1

You are comparing two columns. where is for comparing a column to a value.
where('info->quantity', '<', 'info->low_level_warning') is trying to find rows where info->>quantity is less than the string "info->low_level_warning", which doesn't make much sense.
You should use whereColumn
} else if ($filters['filter'] === 'show_below_min_threshold') {
$query->whereColumn('info->quantity', '<', 'info->low_level_warning');
} else if ($filters['filter'] === 'show_above_max_threshold') {
$query->whereColumn('info->quantity', '>', 'info->high_level_warning');
}