diff --git a/Sources/Subs-Db-mysql.php b/Sources/Subs-Db-mysql.php
index eaf9041e4d..34254851d4 100644
--- a/Sources/Subs-Db-mysql.php
+++ b/Sources/Subs-Db-mysql.php
@@ -840,26 +840,30 @@ function smf_db_insert($method, $table, $columns, $data, $keys, $returnmode = 0,
 			// the inserted value already exists we need to find the pk
 			else
 			{
-				$where_string = '';
-				$count2 = count($keys);
-				for ($x = 0; $x < $count2; $x++)
+				$where_string = [];
+
+				foreach ($columns as $column_name => $type)
 				{
-					$keyPos = array_search($keys[$x], array_keys($columns));
-					$where_string .= $keys[$x] . ' = ' . $data[$i][$keyPos];
-					if (($x + 1) < $count2)
-						$where_string .= ' AND ';
+					if (str_contains($type, 'string-'))
+						$where_string[] = $column_name . ' = ' . sprintf('SUBSTRING({string:%1$s}, 1, ' . substr($type, 7) . ')', $column_name);
+					else
+						$where_string[] = $column_name . ' = ' . sprintf('{%1$s:%2$s}', $type, $column_name);
 				}
 
+				$where_string = implode(' AND ', $where_string);
+
 				$request = $smcFunc['db_query']('', '
-					SELECT `' . $keys[0] . '` FROM ' . $table . '
-					WHERE ' . $where_string . ' LIMIT 1',
-					array()
+					SELECT ' . $keys[0] . '
+					FROM ' . $table . '
+					WHERE ' . $where_string . '
+					LIMIT 1',
+					array_combine($indexed_columns, $data[$i])
 				);
 
 				if ($request !== false && $smcFunc['db_num_rows']($request) == 1)
 				{
 					$row = $smcFunc['db_fetch_assoc']($request);
-					$ai = $row[$keys[0]];
+					$ai = (int) $row[$keys[0]];
 				}
 			}