v1.8.53: fix Redis and MariaDB GUI tabs — wrong client API calls

- redis_tab: fix RedisClient constructor (pass server dict, not alias+store)
- redis_tab: add connect() call, add disconnect on server switch
- redis_tab: remove non-existent db= parameter from execute(), use select_db()
- redis_client: add select_db() method for runtime DB switching
- query_tab: fix use_database() → switch_database(), close() → disconnect()
- query_tab: fix execute() → execute_query() with dict unpacking
- query_tab: add missing connect() call after SQLClient creation

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

core/redis_client.py

@@ -62,6 +62,13 @@ class RedisClient:
         except Exception:
             return False
 
+    def select_db(self, db: int):
+        """Switch to a different Redis database index."""
+        db = int(db)
+        if self._conn is not None and db != self._db:
+            self._conn.execute_command("SELECT", db)
+            self._db = db
+
     # -- commands ---------------------------------------------------------
 
     def execute(self, command: str) -> str:

gui/tabs/query_tab.py

@@ -173,6 +173,9 @@ class QueryTab(ctk.CTkFrame):
                 return
 
             client = SQLClient(server)
+            if not client.connect():
+                self._schedule(self._set_status, t("query_error") + ": connection failed", error=True)
+                return
             databases = client.list_databases()
 
             def _update():
@@ -198,7 +201,7 @@ class QueryTab(ctk.CTkFrame):
         if not self._client:
             return
         try:
-            self._client.use_database(db_name)
+            self._client.switch_database(db_name)
             self._set_status(f"Database: {db_name}")
         except Exception as exc:
             self._set_status(str(exc), error=True)
@@ -206,7 +209,7 @@ class QueryTab(ctk.CTkFrame):
     def _disconnect(self):
         if self._client:
             try:
-                self._client.close()
+                self._client.disconnect()
             except Exception:
                 pass
             self._client = None
@@ -236,7 +239,9 @@ class QueryTab(ctk.CTkFrame):
         """Background thread: execute SQL, measure time, post results."""
         start = time.perf_counter()
         try:
-            columns, rows = self._client.execute(sql)
+            result = self._client.execute_query(sql)
+            columns = result["columns"]
+            rows = result["rows"]
             elapsed = time.perf_counter() - start
 
             def _update():

gui/tabs/redis_tab.py

@@ -105,6 +105,11 @@ class RedisTab(ctk.CTkFrame):
 
     def set_server(self, alias: str | None):
         """Called when user selects a server in sidebar."""
+        if self._client:
+            try:
+                self._client.disconnect()
+            except Exception:
+                pass
         self._current_alias = alias
         self._client = None
         self._command_history.clear()
@@ -143,7 +148,8 @@ class RedisTab(ctk.CTkFrame):
         def _do():
             try:
                 client = self._get_client()
-                result = client.execute(cmd, db=db)
+                client.select_db(db)
+                result = client.execute(cmd)
                 formatted = self._format_result(result)
                 self.after(0, lambda: self._append_output(formatted))
             except Exception as e:
@@ -162,7 +168,13 @@ class RedisTab(ctk.CTkFrame):
 
     def _get_client(self) -> RedisClient:
         if self._client is None:
-            self._client = RedisClient(self._current_alias, self.store)
+            server = self.store.get_server(self._current_alias)
+            if not server:
+                raise ConnectionError(f"Server '{self._current_alias}' not found")
+            self._client = RedisClient(server)
+            if not self._client.connect():
+                self._client = None
+                raise ConnectionError(f"Cannot connect to Redis '{self._current_alias}'")
         return self._client
 
     # ── Stats refresh ──
@@ -175,8 +187,9 @@ class RedisTab(ctk.CTkFrame):
             try:
                 client = self._get_client()
                 db = int(self._db_var.get())
-                keys_count = client.execute("DBSIZE", db=db)
-                info = client.execute("INFO memory", db=db)
+                client.select_db(db)
+                keys_count = client.execute("DBSIZE")
+                info = client.execute("INFO memory")
 
                 # Parse memory from INFO output
                 memory = "—"

version.py

@@ -1,6 +1,6 @@
 """Version info for ServerManager."""
 
-__version__ = "1.8.52"
+__version__ = "1.8.53"
 __app_name__ = "ServerManager"
 __author__ = "aibot777"
 __description__ = "Desktop GUI for managing remote servers"