added param binding examples for update() and delete()

fixes #14218

framework/db/Command.php

@@ -472,6 +472,13 @@ class Command extends Component
      * $connection->createCommand()->update('user', ['status' => 1], 'age > 30')->execute();
      * ```
      *
+     * or with using parameter binding for the condition:
+     *
+     * ```php
+     * $minAge = 30;
+     * $connection->createCommand()->update('user', ['status' => 1], 'age > :minAge', [':minAge' => $minAge])->execute();
+     * ```
+     *
      * The method will properly escape the column names and bind the values to be updated.
      *
      * Note that the created command is not executed until [[execute()]] is called.
@@ -498,6 +505,13 @@ class Command extends Component
      * $connection->createCommand()->delete('user', 'status = 0')->execute();
      * ```
      *
+     * or with using parameter binding for the condition:
+     *
+     * ```php
+     * $status = 0;
+     * $connection->createCommand()->delete('user', 'status = :status', [':status' => $status])->execute();
+     * ```
+     *
      * The method will properly escape the table and column names.
      *
      * Note that the created command is not executed until [[execute()]] is called.