fix(iotdb): load databases without duplicate schema

agents/drivers/iotdb/src/main/java/com/dbx/agent/iotdb/IoTDBAgent.java

@@ -1,8 +1,13 @@
 package com.dbx.agent.iotdb;
 
 import com.dbx.agent.ConfiguredJdbcAgent;
+import com.dbx.agent.DatabaseInfo;
 import com.dbx.agent.JdbcAgentProfile;
 import com.dbx.agent.JsonRpcServer;
+import java.sql.ResultSet;
+import java.sql.Statement;
+import java.util.ArrayList;
+import java.util.List;
 
 public final class IoTDBAgent extends ConfiguredJdbcAgent {
     public static final JdbcAgentProfile IOTDB_PROFILE = new JdbcAgentProfile(
@@ -16,6 +21,25 @@ public final class IoTDBAgent extends ConfiguredJdbcAgent {
         super(IOTDB_PROFILE);
     }
 
+    // IoTDB 的 database 是 `root.xxx` 路径前缀；JDBC metadata 会把同一路径同时投影成 catalog/schema。
+    // 这里使用 IoTDB 原生语句作为 database 列表来源，避免依赖驱动的关系型兼容层。
+    @Override
+    public List<DatabaseInfo> listDatabases() {
+        return unchecked(() -> {
+            List<DatabaseInfo> result = new ArrayList<>();
+            try (Statement stmt = requireConnection().createStatement();
+                 ResultSet rs = stmt.executeQuery("SHOW DATABASES")) {
+                while (rs.next()) {
+                    String name = rs.getString(1);
+                    if (name != null && !name.trim().isEmpty()) {
+                        result.add(new DatabaseInfo(name.trim()));
+                    }
+                }
+            }
+            return result;
+        });
+    }
+
     public static void main(String[] args) {
         new JsonRpcServer(new IoTDBAgent()).run();
     }