fix(tdengine): keep database context when viewing tables

apps/desktop/src/lib/__tests__/database/jdbcDialect.spec.ts

@@ -92,6 +92,19 @@ describe("jdbc dialect inference", () => {
     ).toBe("sqlserver");
   });
 
+  it("detects TDengine JDBC connections and keeps the selected database in the object tree", () => {
+    const connection = {
+      db_type: "jdbc" as const,
+      connection_string: "jdbc:TAOS-RS://tdengine.example:6041/",
+      jdbc_driver_class: "com.taosdata.jdbc.rs.RestfulDriver",
+    };
+
+    expect(inferJdbcDialect(connection)).toBe("tdengine");
+    expect(effectiveDatabaseTypeForConnection(connection)).toBe("tdengine");
+    expect(connectionUsesDatabaseObjectTreeMode(connection)).toBe(false);
+    expect(connectionObjectTreeQuerySchema(connection, "dbx_test")).toBe("dbx_test");
+  });
+
   it("keeps Phoenix as generic JDBC while preserving its schema tree", () => {
     const connection = { db_type: "jdbc" as const, driver_profile: "phoenix" };
 

apps/desktop/src/lib/database/jdbcDialect.ts

@@ -38,6 +38,7 @@ const JDBC_DIALECT_MATCHERS: Array<{ type: DatabaseType; patterns: RegExp[] }> =
   { type: "sqlserver", patterns: [/jdbc:sqlserver:/i, /sqlserver/i, /mssql/i] },
   { type: "oracle", patterns: [/jdbc:oracle:/i, /oracle/i] },
   { type: "clickhouse", patterns: [/jdbc:clickhouse:/i, /clickhouse/i] },
+  { type: "tdengine", patterns: [/jdbc:taos(?:-rs|-ws)?:/i, /taosdata/i, /tdengine/i] },
   { type: "h2", patterns: [/jdbc:h2:/i, /\bh2\b/i] },
   { type: "sqlite", patterns: [/jdbc:sqlite:/i, /sqlite/i] },
   { type: "db2", patterns: [/jdbc:db2:/i, /\bdb2\b/i] },
@@ -214,6 +215,8 @@ export function connectionUsesDatabaseObjectTreeMode(connection?: JdbcDialectCon
   const dialect = inferJdbcDialect(connection);
   if (!dialect) return true;
   if (dialect === "hive" || dialect === "trino") return false;
+  // TDengine exposes databases as the top-level namespace, without schemas.
+  if (dialect === "tdengine") return false;
   if (dialect === "databend") return true;
   return !usesTreeSchemaMode(dialect);
 }