Support compare in MongoDB

CHANGELOG.md

@@ -4,6 +4,7 @@ Yii Framework 2 mongodb extension Change Log
 2.0.5 under development
 -----------------------
 
+- Enh #2022: Added support for querying on values using basic generic operators to `yii\mongodb\Query`
 
 2.0.4 May 10, 2015
 ------------------

Collection.php

@@ -844,21 +844,45 @@ public function buildCondition($condition)
             return [];
         }
         if (isset($condition[0])) { // operator format: operator, operand 1, operand 2, ...
-            $operator = strtoupper($condition[0]);
-            if (isset($builders[$operator])) {
+            $operator = $condition[0];
+            if (strncmp($operator, '$', 1) === 0) {
+                $method = 'buildSimpleCondition';
+            } elseif (isset($builders[strtoupper($operator)])) {
+                $operator = strtoupper($operator);
                 $method = $builders[$operator];
-                array_shift($condition);
-
-                return $this->$method($operator, $condition);
             } else {
                 throw new InvalidParamException('Found unknown operator in query: ' . $operator);
             }
+            array_shift($condition);
+            return $this->$method($operator, $condition);
         } else {
             // hash format: 'column1' => 'value1', 'column2' => 'value2', ...
             return $this->buildHashCondition($condition);
         }
     }
-
+
+    /**
+     * Creates a condition on a column-value pair using an abritrary operator
+     * 
+     * @param string $operator The Mongo operator. Note that Mongo query operators must start with an $ (e.g. `$gt`, `$lt`, etc.)
+     * @param array $operands The column-value pair
+     * @return array The generated Mongo condition
+     * @throws InvalidParamException if $operator does not start with $ or when wrong number of operands have been given.
+     */
+    public function buildSimpleCondition($operator, $operands)
+    {
+        if (strncmp($operator, '$', 1) !== 0) {
+            throw new InvalidParamException('Invalid operator in query: ' . $operator);
+        }
+        if (!isset($operands[0], $operands[1])) {
+            throw new InvalidParamException("Operator '$operator' requires two operands.");
+        }
+
+        list($name, $value) = $operands;
+
+        return [$name => [$operator => $value]];
+    }
+
     /**
      * Creates a condition based on column-value pairs.
      * @param array $condition the condition specification.

Query.php

@@ -414,4 +414,64 @@ private function composeSort()
         }
         return $sort;
     }
+
+    /**
+     * Helper method for easy querying on values containing some common operators.
+     *
+     * The comparison operator is intelligently determined based on the first few characters in the given value and 
+     * internally translated to a MongoDB operator.
+     * In particular, it recognizes the following operators if they appear as the leading characters in the given value:
+     * <: the column must be less than the given value ($lt).
+     * >: the column must be greater than the given value ($gt).
+     * <=: the column must be less than or equal to the given value ($lte).
+     * >=: the column must be greater than or equal to the given value ($gte).
+     * <>: the column must not be the same as the given value ($ne). Note that when $partialMatch is true, this would mean the value must not be a substring of the column.
+     * =: the column must be equal to the given value ($eq).
+     * none of the above: use the $defaultOperator
+     *
+     * Note that when the value is empty, no comparison expression will be added to the search condition.
+     *
+     * @param string $name column name
+     * @param scalar $value column value
+     * @param string $defaultOperator Defaults to =, performing an exact match.
+     * For example: use 'LIKE' or 'REGEX' for partial cq regex matching 
+     * @see yii\mongodb\Collection::buildCondition() 
+     * @return static The Query object itself
+    */
+    public function andFilterCompare($name, $value, $defaultOperator = '=')
+    {        
+        $matches=[];
+        if (preg_match("/^(<>|>=|>|<=|<|=)/", $value, $matches)) {
+            $op = $matches[1];
+            $value = substr($value, strlen($op));
+        } else {
+            $op = $defaultOperator;
+        }
+
+        $op = $this->normalizeOperator($op);
+
+        return $this->andFilterWhere([$op, $name, $value]);
+    }
+
+    /**
+     * Converts "\yii\db\*" quick condition operator into actual Mongo condition operator.
+     * @param string $key raw operator.
+     * @return string actual key.
+     */
+    protected function normalizeOperator($key)
+    {
+        static $map = [
+            '=' => '$eq',
+            '>' => '$gt',
+            '>=' => '$gte',
+            '<' => '$lt',
+            '<=' => '$lte',
+            '<>' => '$ne',
+        ];
+        if (array_key_exists($key, $map)) {
+            return $map[$key];
+        } else {
+            return $key;
+        }
+    }
 }