diff --git a/chat2db-server/chat2db-plugins/chat2db-dm/src/main/java/ai/chat2db/plugin/dm/DMMetaData.java b/chat2db-server/chat2db-plugins/chat2db-dm/src/main/java/ai/chat2db/plugin/dm/DMMetaData.java
index fc2db852..ec0275c1 100644
--- a/chat2db-server/chat2db-plugins/chat2db-dm/src/main/java/ai/chat2db/plugin/dm/DMMetaData.java
+++ b/chat2db-server/chat2db-plugins/chat2db-dm/src/main/java/ai/chat2db/plugin/dm/DMMetaData.java
@@ -33,35 +33,38 @@ public class DMMetaData extends DefaultMetaService implements MetaData {
         return "\"" + tableName + "\"";
       }
 
-    public String tableDDL(Connection connection, String databaseName, String schemaName, String tableName) {
-        String sql = """
-                     SELECT
-                         (SELECT comments FROM user_tab_comments WHERE table_name = '%s') AS comments,
-                         (SELECT dbms_metadata.get_ddl('TABLE', '%s', '%s') FROM dual) AS ddl
-                     FROM dual;
-                     """;
+    private static String tableDDL = "SELECT dbms_metadata.get_ddl('TABLE', '%s','%s') as ddl FROM dual ;";
+    private static String tableComment = "select COMMENTS from dba_tab_comments where OWNER='%s' and TABLE_TYPE='TABLE' and TABLE_NAME='%s';";
+    private static String columnComment = "SELECT COLNAME,COMMENT$ FROM SYS.SYSCOLUMNCOMMENTS where SCHNAME = '%s' and TVNAME = '%s' and TABLE_TYPE = 'TABLE';";
+
+    public String tableDDL(Connection connection, String databaseName, String schemaName, String tableName)  {
+        String tableDDLSql = String.format(tableDDL, tableName, schemaName);
+        String tableCommentSql = String.format(tableComment, schemaName, tableName);
+        String columnCommentSql = String.format(columnComment, schemaName, tableName);
         StringBuilder ddlBuilder = new StringBuilder();
-        String tableDDLSql = String.format(sql, tableName, tableName, schemaName);
         SQLExecutor.getInstance().execute(connection, tableDDLSql, resultSet -> {
             if (resultSet.next()) {
                 String ddl = resultSet.getString("ddl");
-                String comment = resultSet.getString("comments");
-                if (StringUtils.isNotBlank(comment)) {
-                    ddlBuilder.append(ddl).append("\n").append("COMMENT ON TABLE ").append(format(schemaName))
-                            .append(".").append(format(tableName)).append(" IS ").append("'").append(comment).append("';");
+                ddlBuilder.append(ddl).append("\n");
+            }
+        });
+        SQLExecutor.getInstance().execute(connection, tableCommentSql, resultSet -> {
+            if (resultSet.next()) {
+                String comments = resultSet.getString("COMMENTS");
+                if (Objects.nonNull(comments)) {
+                    ddlBuilder.append("COMMENT ON TABLE ").append(format(schemaName)).append(".").append(format(tableName))
+                            .append(" IS ").append(comments).append(";").append("\n");
                 }
             }
         });
-        String columnCommentsSql =String.format("select COLNAME,COMMENT$ from SYS.SYSCOLUMNCOMMENTS\n" +
-                                          "where SCHNAME = '%s' and TVNAME = '%s'and TABLE_TYPE = 'TABLE';", schemaName,tableName);
-           SQLExecutor.getInstance().execute(connection, columnCommentsSql, resultSet->{
-               while (resultSet.next()) {
-                   String columnName = resultSet.getString("COLNAME");
-                   String comment = resultSet.getString("COMMENT$");
-                   ddlBuilder.append("COMMENT ON COLUMN ").append(format(schemaName)).append(".").append(format(tableName))
-                           .append(".").append(format(columnName)).append(" IS ").append("'").append(comment).append("';").append("\n");
-               }
-           });
+        SQLExecutor.getInstance().execute(connection, columnCommentSql, resultSet -> {
+            while (resultSet.next()) {
+                String columnName = resultSet.getString("COLNAME");
+                String comment = resultSet.getString("COMMENT$");
+                ddlBuilder.append("COMMENT ON COLUMN ").append(format(schemaName)).append(".").append(format(tableName))
+                        .append(".").append(format(columnName)).append(" IS ").append("'").append(comment).append("';").append("\n");
+            }
+        });
         return ddlBuilder.toString();
     }
 
diff --git a/chat2db-server/chat2db-plugins/chat2db-mysql/src/main/java/ai/chat2db/plugin/mysql/MysqlMetaData.java b/chat2db-server/chat2db-plugins/chat2db-mysql/src/main/java/ai/chat2db/plugin/mysql/MysqlMetaData.java
index c802176e..626a60b4 100644
--- a/chat2db-server/chat2db-plugins/chat2db-mysql/src/main/java/ai/chat2db/plugin/mysql/MysqlMetaData.java
+++ b/chat2db-server/chat2db-plugins/chat2db-mysql/src/main/java/ai/chat2db/plugin/mysql/MysqlMetaData.java
@@ -125,8 +125,8 @@ public class MysqlMetaData extends DefaultMetaService implements MetaData {
         String sql = "SHOW PROCEDURE STATUS WHERE Db = DATABASE()";
        return SQLExecutor.getInstance().execute(connection, sql, resultSet -> {
            ArrayList<Procedure> procedures = new ArrayList<>();
-           Procedure procedure = new Procedure();
            while (resultSet.next()){
+               Procedure procedure = new Procedure();
                procedure.setProcedureName(resultSet.getString("Name"));
                procedures.add(procedure);
            }