Fixes #17345: Improved performance of `yii\db\Connection::quoteColumn…

…Name()`

framework/CHANGELOG.md

@@ -5,6 +5,7 @@ Yii Framework 2 Change Log
 ------------------------
 
 - Bug #17341: Fixed error from yii.activeForm.js in strict mode (mikehaertl)
+- Enh #17345: Improved performance of `yii\db\Connection::quoteColumnName()` (brandonkelly)
 
 
 2.0.20 June 04, 2019

framework/db/Connection.php

@@ -441,6 +441,10 @@ class Connection extends Component
      * @var array query cache parameters for the [[cache()]] calls
      */
     private $_queryCacheInfo = [];
+    /**
+     * @var string[] quoted column name cache for [[quoteColumnName()]] calls
+     */
+    private $_quotedColumnNames;
 
 
     /**
@@ -904,7 +908,10 @@ public function quoteTableName($name)
      */
     public function quoteColumnName($name)
     {
-        return $this->getSchema()->quoteColumnName($name);
+        if (isset($this->_quotedColumnNames[$name])) {
+            return $this->_quotedColumnNames[$name];
+        }
+        return $this->_quotedColumnNames[$name] = $this->getSchema()->quoteColumnName($name);
     }
 
     /**