fix(scheme): 改进MySQL表注释获取与对比的可靠性

extend/base/common/service/scheme/DbToSchemeService.php

@@ -57,17 +57,32 @@ class DbToSchemeService
 
     protected function getTableComment($tableName): string
     {
-        // 简单适配 MySQL
-        try {
-            $config = Config::get('database.connections.' . $this->connection);
-            $database = $config['database'];
-            // 暂时只支持MySQL的表注释获取，其他返回空
-            $sql = "SELECT table_comment FROM information_schema.TABLES WHERE table_schema = ? AND table_name = ?";
-            $res = Db::connect($this->connection)->query($sql, [$database, $tableName]);
-            return $res[0]['table_comment'] ?? '';
-        } catch (\Exception $e) {
+        $type = strtolower((string)Config::get('database.connections.' . $this->connection . '.type', ''));
+        if ($type !== 'mysql') {
             return '';
         }
+
+        try {
+            $escaped = addcslashes($tableName, "\\_%");
+            $rows = Db::connect($this->connection)->query("SHOW TABLE STATUS LIKE '$escaped'");
+            if (!empty($rows)) {
+                return isset($rows[0]['Comment']) ? (string)$rows[0]['Comment'] : '';
+            }
+        } catch (\Exception $e) {
+        }
+
+        try {
+            $rows = Db::connect($this->connection)->query("SHOW CREATE TABLE `$tableName`");
+            if (!empty($rows)) {
+                $create = $rows[0]['Create Table'] ?? '';
+                if ($create !== '' && preg_match("/COMMENT='(.*?)'/s", $create, $matches)) {
+                    return stripcslashes($matches[1]);
+                }
+            }
+        } catch (\Exception $e) {
+        }
+
+        return '';
     }
 
     protected function getTableIndices($tableName): array