Use IN() / NOT IN() when possible

resolves  #2937

CHANGELOG-v3.md

@@ -14,6 +14,7 @@
 - `craft\helpers\StringHelper::asciiCharMap()` now has `$flat` and `$language` arguments.
 - Craft no longer saves new versions of entries when absolutely nothing changed about them in the save request. ([#2923](https://github.com/craftcms/cms/issues/2923))
 - `minVersionRequired` is no longer enforced on a plugin when updating it if was coming from a `dev-` branch.
+- Improved the performance of element queries when a lot of values were passed into a param, such as `id`, by using `IN()` and `NOT IN()` conditions when possible. ([#2937](https://github.com/craftcms/cms/pull/2937))
 
 ### Deprecated
 - Deprecated the `customAsciiCharMappings` config setting. (Any corrections to ASCII char mappings should be submitted to [Stringy](https://github.com/danielstjules/Stringy).)

src/helpers/Db.php

@@ -457,6 +457,9 @@ public static function parseParam(string $column, $value, string $defaultOperato
         $condition = [$glue];
         $isMysql = Craft::$app->getDb()->getIsMysql();
 
+        $inVals = [];
+        $notInVals = [];
+
         foreach ($value as $val) {
             self::_normalizeEmptyValue($val);
             $operator = self::_parseParamOperator($val, $defaultOperator);
@@ -522,9 +525,29 @@ public static function parseParam(string $column, $value, string $defaultOperato
                 }
             }
 
+            // ['or', 1, 2, 3] => IN (1, 2, 3)
+            if ($glue == 'or' && $operator === '=') {
+                $inVals[] = $val;
+                continue;
+            }
+
+            // ['and', '!=1', '!=2', '!=3'] => NOT IN (1, 2, 3)
+            if ($glue == 'and' && $operator === '!=') {
+                $notInVals[] = $val;
+                continue;
+            }
+
             $condition[] = [$operator, $column, $val];
         }
 
+        if (!empty($inVals)) {
+            $condition[] = ['in', $column, $inVals];
+        }
+
+        if (!empty($notInVals)) {
+            $condition[] = ['not in', $column, $notInVals];
+        }
+
         return $condition;
     }