# DB Querier Tool
## Description
The `db_querier` tool is a Go-based gRPC service that executes a raw SQL query against a specified **SQLite** database file. It is designed for reading data but can execute any valid SQL statement.
> **Warning:** This tool can execute any SQL query provided to it, including destructive ones like `UPDATE`, `DELETE`, or `DROP TABLE`. Use with extreme caution, as it can lead to permanent data loss.
## Parameters
The tool accepts the following arguments in a JSON object:
| Parameter | Type | Required | Description |
|-----------|----------|----------|--------------------------------------------------------------|
| `db_path` | `string` | **Yes** | The local file path to the SQLite database (e.g., `./data/main.db`). |
| `query` | `string` | **Yes** | The SQL query to execute. |
For security, the tool verifies that the database file exists before attempting to connect.
## Response
* **Successful Query:** If the query executes successfully, the tool returns a JSON array of objects. Each object represents a row, with keys corresponding to the column names. An empty array `[]` is returned if the query yields no results.
* **Error:** If the database file is not found, the SQL query is invalid, or another error occurs, the tool returns an error message.
## Usage Example
Here is an example of how to use the `db_querier` tool to select all users from a `users` table in a SQLite database file named `project.db`.
**Request:**
```bash
curl -X POST http://localhost:8002/v1/tools:run \
-d '{
"name": "db_querier",
"arguments": {
"db_path": "data/project.db",
"query": "SELECT id, name, email FROM users WHERE status = 'active';"
}
}'
```
**Successful Response:**
```json
{
"result": {
"listValue": {
"values": [
{
"structValue": {
"fields": {
"id": { "numberValue": 1 },
"name": { "stringValue": "Alice" },
"email": { "stringValue": "alice@example.com" }
}
}
},
{
"structValue": {
"fields": {
"id": { "numberValue": 2 },
"name": { "stringValue": "Bob" },
"email": { "stringValue": "bob@example.com" }
}
}
}
]
}
}
}
```
## Configuration
The tool's configuration is managed through a `config.json` file located in the tool's directory.
**Example `config.json`:**
```json
{
"port": 50053,
"command": ["go", "run", "."]
}
```
* `port`: The port on which the tool's gRPC server will listen.
* `command`: The command and arguments to execute the tool.
## Health and Logging
* **Health Checks:** This tool implements the standard gRPC Health Checking Protocol.
* **Logging:** The tool uses a structured JSON logger (`slog`) for observability.
