QueryCheck for PHP

QueryCheck is a logical JSON query evaluator which uses the MongoDB query style.

This is a PHP 8.3+ port of the original JavaScript/Node.js querycheck package.

Supported Operators

Comparison Operators

• $eq - Matches values that are equal to a specified value
• $ne - Matches values that are not equal to a specified value
• $gt - Matches values that are greater than a specified value
• $gte - Matches values that are greater than or equal to a specified value
• $lt - Matches values that are less than a specified value
• $lte - Matches values that are less than or equal to a specified value
• $in - Matches any of the values specified in an array
• $regex - Matches values using regular expression pattern matching

Logical Operators

• $and - Joins query clauses with a logical AND
• $or - Joins query clauses with a logical OR
• $not - Inverts the effect of a query expression

Aggregation Expressions ($expr)

• $expr - Allows aggregation expressions within query predicates

The following operators can be used within $expr:

Arithmetic Operators:

• $add - Adds numbers together
• $subtract - Subtracts two numbers
• $multiply - Multiplies numbers together
• $divide - Divides two numbers
• $mod - Returns the modulo of two numbers

Query Operators (for aggregation context):

• $eq - Returns true if values are equal
• $ne - Returns true if values are not equal
• $gt - Returns true if first value is greater than second
• $gte - Returns true if first value is greater than or equal to second
• $lt - Returns true if first value is less than second
• $lte - Returns true if first value is less than or equal to second

Logical Operators:

• $not - Returns the boolean opposite of an expression
• $in - Returns true if a value is in an array

Conditional Operators:

• $cond - Conditional expression with if/then/else branches

Field References: Field references within $expr use MongoDB syntax with $ prefix (e.g., $fieldName, $customer.address.city).

Installation

Install with Composer:

composer require maurice2k/querycheck

Simple Example

<?php

use Maurice2k\QueryCheck\QueryCheck;

$vars = [
    'now' => [
        'isoDate' => '2020-05-21',
        'isoTime' => '13:59:48',
    ]
];

$openingHours = new QueryCheck([
    'now.isoDate' => [
        '$not' => [
            '$in' => ['2019-12-25', '2019-12-26', '2019-12-31', '2020-01-01']
        ]
    ],
    'now.isoTime' => [
        '$gt' => '10:00',
        '$lt' => '18:00'
    ]
]);

if ($openingHours->test($vars)) {
    echo "We're OPEN!\n";
} else {
    echo "Sorry, we're CLOSED!\n";
}

Using $expr for Aggregation Expressions

The $expr operator allows you to use aggregation expressions for field-to-field comparisons and calculations:

<?php

use Maurice2k\QueryCheck\QueryCheck;

// Compare two fields
$budget = new QueryCheck([
    '$expr' => [
        '$gt' => ['$spent', '$budget']  // spent > budget
    ]
]);

$data = ['spent' => 450, 'budget' => 400];
$budget->test($data); // returns true

// Arithmetic operations
$total = new QueryCheck([
    '$expr' => [
        '$gte' => [
            ['$add' => ['$subtotal', '$tax', '$shipping']],
            100
        ]
    ]
]);

$data = ['subtotal' => 80, 'tax' => 10, 'shipping' => 15];
$total->test($data); // returns true (80 + 10 + 15 = 105 >= 100)

// Conditional expressions
$discount = new QueryCheck([
    '$expr' => [
        '$lt' => [
            [
                '$cond' => [
                    'if' => ['$gte' => ['$qty', 100]],
                    'then' => ['$multiply' => ['$price', 0.5]],
                    'else' => ['$multiply' => ['$price', 0.75]]
                ]
            ],
            60
        ]
    ]
]);

$data = ['qty' => 150, 'price' => 100];
$discount->test($data); // returns true (qty >= 100, so discounted price = 100 * 0.5 = 50, and 50 < 60 is true)

// Logical operators - $not
$notGreater = new QueryCheck([
    '$expr' => [
        '$not' => [
            ['$gt' => ['$qty', 250]]
        ]
    ]
]);

$data = ['qty' => 200];
$notGreater->test($data); // returns true (qty is NOT > 250)

// Logical operators - $in
$inStock = new QueryCheck([
    '$expr' => [
        '$in' => ['$fruit', '$in_stock']
    ]
]);

$data = ['fruit' => 'banana', 'in_stock' => ['apple', 'banana', 'cherry']];
$inStock->test($data); // returns true (banana is in the in_stock array)

// Combining $not and $in
$notRestricted = new QueryCheck([
    '$expr' => [
        '$not' => [
            ['$in' => ['$category', '$restricted_categories']]
        ]
    ]
]);

$data = ['category' => 'electronics', 'restricted_categories' => ['weapons', 'alcohol']];
$notRestricted->test($data); // returns true (electronics is NOT in restricted categories)

Notes:

• Field references in $expr require the $ prefix (e.g., $fieldName). Without the prefix, values are treated as literals.
• $expr can be combined with $and and $or operators to mix regular field queries with aggregation expressions.
• The aggregation $not operator evaluates false, null, and 0 as false; all other values (including non-zero numbers and arrays) as true.
• The aggregation $in operator checks if a value exists in an array, similar to the query $in but used within expressions.

PHP vs JavaScript Differences

Undefined Values

In JavaScript, accessing a non-existent property returns undefined. In PHP, there is no undefined type.

To handle this difference, the PHP version:

• Undefined in PHP means a key doesn't exist in an array (checked with !isset() or !array_key_exists())
• When a key doesn't exist, it's treated as null internally, but the comparison logic distinguishes between actual null values and non-existent keys
• By default, non-existent keys (undefined) do NOT equal null
• You can use setUndefinedEqualsNull(true) to make undefined values equal to null

$qc = new QueryCheck(['nonExistent' => null]);
$qc->setUndefinedEqualsNull(true);
$qc->test(['someKey' => 'value']); // returns true - nonExistent is undefined, treated as null

Arrays vs Objects

PHP uses arrays for both lists and associative arrays (objects). The package automatically detects:

• Sequential numeric arrays (list-style) are treated as arrays
• Associative arrays are treated as objects/hashes

Advanced Features

Strict Mode

Enable strict type checking:

$qc = new QueryCheck(['age' => '30']);
$qc->setStrictMode(true);
$qc->test(['age' => 30]); // throws StrictTypeError - strict type mismatch

Custom Operand Evaluator

You can extend QueryCheck with custom operand evaluation functions. The operand evaluator works with both regular query operators and $expr aggregation expressions:

$qc = new QueryCheck([
    'fullName' => ['$concat' => ['$var' => 'firstName'], ' ', ['$var' => 'lastName']]
]);

// Or use with $expr:
$qc = new QueryCheck([
    '$expr' => [
        '$gt' => [
            ['$multiply' => [['$var' => 'price'], ['$var' => 'multiplier']]],
            150
        ]
    ]
]);

$qc->setOperandEvaluator(function($operand, $data) use ($qc) {
    // Custom evaluation logic
    if (is_array($operand) && isset($operand['$var'])) {
        return $qc->getVariableValue($operand['$var'], $data);
    }
    if (is_array($operand) && isset($operand['$concat'])) {
        return implode('', array_map(
            fn($item) => is_string($item) ? $item : $this($item, $data),
            $operand['$concat']
        ));
    }
    return $operand;
});

Testing

Run the test suite:

composer install
./vendor/bin/phpunit

License

QueryCheck is available under the MIT license.