From a51fb14cc14e0680a584a11845ee920d9fb8e65d Mon Sep 17 00:00:00 2001
From: Lainow <texamaxsam61@gmail.com>
Date: Tue, 2 Sep 2025 14:25:15 +0200
Subject: [PATCH] Fix coalesce part in multiple dropdown sql query

---
 CHANGELOG.md           | 1 +
 inc/dropdown.class.php | 4 ++--
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index eab06bb1..1951c2cd 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Fixed
 
+- Fix for the `COALESCE` part of the `SQL query` for `multiple` dropdowns
 - Fix `search option` for `multiple` dropdown
 
 ## [1.21.23] - 2025-08-26
diff --git a/inc/dropdown.class.php b/inc/dropdown.class.php
index 02d092d4..bc239677 100644
--- a/inc/dropdown.class.php
+++ b/inc/dropdown.class.php
@@ -262,13 +262,13 @@ public static function multipleDropdownAddWhere($link, $tablefield, $field, $val
 
         // Determines the default value
         $default_value = $field_field->fields['default_value'] ?? '';
-        $default_value = ($default_value == '[]') ? '' : $DB->quoteValue($default_value);
+        $default_value = ($default_value == '[]') ? '""' : $DB->quoteValue($default_value);
 
         // Constructs the SQL query base
         $quotedField = $DB->quoteName($tablefield) . '.' . $DB->quoteName($field);
         $sqlBase = $link . ' COALESCE(' . $quotedField . ', ' . $default_value . ')';
 
-        // Handles “equals” and “notequals” cases in a unified manner
+        // Handles "equals" and "notequals" cases in a unified manner
         $operator = ($searchtype === 'equals') ? '' : 'NOT ';
         $condition = ($val == '0')
             ? $operator . 'IN("", "[]")'