add

backend/sql/04_country.sql

@@ -98,17 +98,19 @@ BEGIN
     CREATE OR REPLACE VIEW country_info_view AS
     SELECT 
         u.id AS country_id,
-        n.name AS name,
-        c.code AS code,
-        u.deleted AS deleted
+        n.name AS country_name,       -- 国家名称
+        c.code AS country_code,       -- 国家代码
+        f.flag AS country_flag,       -- 国旗信息
     FROM 
         country u
-    JOIN 
-        country_name n ON u.id = n.country_id
-    JOIN 
-        country_code c ON u.id = c.country_id
+    LEFT JOIN 
+        country_name n ON u.id = n.country_id AND n.deleted = FALSE  -- 过滤已删除名称
+    LEFT JOIN 
+        country_code c ON u.id = c.country_id AND c.deleted = FALSE  -- 过滤已删除代码
+    LEFT JOIN 
+        country_flag f ON u.id = f.country_id AND f.deleted = FALSE  -- 左连接：允许无国旗数据
     WHERE
-        u.deleted = FALSE;
+        u.deleted = FALSE;  -- 只查询未删除的国家
 
     -- 根据视图是否已存在输出不同提示
     IF view_exists THEN