chore: add default value to CHDB_DATA_PATH

Author: wudidapaopao

.github/workflows/ci.yaml

@@ -39,7 +39,6 @@ jobs:
           CLICKHOUSE_SECURE: "false"
           CLICKHOUSE_VERIFY: "false"
           CHDB_ENABLED: "true"
-          CHDB_DATA_PATH: ":memory:"
         run: |
           uv run pytest tests
 

README.md

@@ -227,8 +227,8 @@ The following environment variables are used to configure the ClickHouse and chD
   * Default: `"false"`
   * Set to `"true"` to enable chDB tools
 * `CHDB_DATA_PATH`: The path to the chDB data directory
-  * Required when `CHDB_ENABLED=true`
-  * Use `:memory:` for in-memory database (recommended for testing)
+  * Default: `":memory:"` (in-memory database) 
+  * Use `:memory:` for in-memory database
   * Use a file path for persistent storage (e.g., `/path/to/chdb/data`)
 
 #### Example Configurations
@@ -274,7 +274,7 @@ For chDB only (in-memory):
 # chDB configuration
 CHDB_ENABLED=true
 CLICKHOUSE_ENABLED=false
-CHDB_DATA_PATH=:memory:
+# CHDB_DATA_PATH defaults to :memory:
 ```
 
 For chDB with persistent storage:

mcp_clickhouse/mcp_env.py

@@ -197,7 +197,7 @@ def enabled(self) -> bool:
     @property
     def data_path(self) -> str:
         """Get the chDB data path."""
-        return os.environ["CHDB_DATA_PATH"]
+        return os.getenv("CHDB_DATA_PATH", ":memory:")
 
     def get_client_config(self) -> dict:
         """Get the configuration dictionary for chDB client.
@@ -215,8 +215,7 @@ def _validate_required_vars(self) -> None:
         Raises:
             ValueError: If any required environment variable is missing.
         """
-        if self.enabled and "CHDB_DATA_PATH" not in os.environ:
-            raise ValueError("Missing required environment variable: CHDB_DATA_PATH")
+        pass
 
 
 # Global instance placeholders for the singleton pattern

mcp_clickhouse/mcp_server.py

@@ -328,7 +328,8 @@ def _init_chdb_client():
 
 if get_chdb_config().enabled:
     _chdb_client = _init_chdb_client()
-    atexit.register(lambda: _chdb_client.close() if _chdb_client is not None else None)
+    if _chdb_client:
+        atexit.register(lambda: _chdb_client.close())
 
     mcp.add_tool(run_chdb_select_query)
     chdb_prompt = Prompt.from_function(