database_mcp_postgres/tools/
drop_database.rs

1//! MCP tool: `drop_database`.
2
3use std::borrow::Cow;
4
5use database_mcp_server::AppError;
6use database_mcp_server::types::{DropDatabaseRequest, MessageResponse};
7use database_mcp_sql::Connection as _;
8use database_mcp_sql::identifier::validate_identifier;
9use rmcp::handler::server::router::tool::{AsyncTool, ToolBase};
10use rmcp::model::{ErrorData, ToolAnnotations};
11
12use crate::PostgresHandler;
13
14/// Marker type for the `drop_database` MCP tool.
15pub(crate) struct DropDatabaseTool;
16
17impl DropDatabaseTool {
18    const NAME: &'static str = "drop_database";
19    const DESCRIPTION: &'static str = r#"Drop an existing database from the connected server.
20
21<usecase>
22Use when:
23- Removing a database that is no longer needed
24- Cleaning up test or temporary databases
25</usecase>
26
27<examples>
28✓ "Drop the test_db database" → drop_database(database_name="test_db")
29✗ "Drop a table" → use drop_table instead
30</examples>
31
32<safety>
33IMPORTANT: This permanently deletes the database and ALL its data. This action cannot be undone.
34Cannot drop the database you are currently connected to.
35</safety>
36
37<what_it_returns>
38A confirmation message with the dropped database name.
39</what_it_returns>"#;
40}
41
42impl ToolBase for DropDatabaseTool {
43    type Parameter = DropDatabaseRequest;
44    type Output = MessageResponse;
45    type Error = ErrorData;
46
47    fn name() -> Cow<'static, str> {
48        Self::NAME.into()
49    }
50
51    fn description() -> Option<Cow<'static, str>> {
52        Some(Self::DESCRIPTION.into())
53    }
54
55    fn annotations() -> Option<ToolAnnotations> {
56        Some(
57            ToolAnnotations::new()
58                .read_only(false)
59                .destructive(true)
60                .idempotent(false)
61                .open_world(false),
62        )
63    }
64}
65
66impl AsyncTool<PostgresHandler> for DropDatabaseTool {
67    async fn invoke(handler: &PostgresHandler, params: Self::Parameter) -> Result<Self::Output, Self::Error> {
68        Ok(handler.drop_database(&params).await?)
69    }
70}
71
72impl PostgresHandler {
73    /// Drops an existing database.
74    ///
75    /// Refuses to drop the currently connected (default) database and
76    /// evicts the corresponding pool cache entry after a successful drop.
77    ///
78    /// # Errors
79    ///
80    /// Returns [`AppError::ReadOnlyViolation`] in read-only mode,
81    /// [`AppError::InvalidIdentifier`] for invalid names,
82    /// or [`AppError::Query`] if the target is the active database
83    /// or the backend reports an error.
84    pub async fn drop_database(&self, request: &DropDatabaseRequest) -> Result<MessageResponse, AppError> {
85        if self.config.read_only {
86            return Err(AppError::ReadOnlyViolation);
87        }
88        let name = &request.database_name;
89        validate_identifier(name)?;
90
91        // Guard: prevent dropping the currently connected database.
92        if self.connection.default_database_name() == name.as_str() {
93            return Err(AppError::Query(format!(
94                "Cannot drop the currently connected database '{name}'."
95            )));
96        }
97
98        let drop_sql = format!("DROP DATABASE {}", self.connection.quote_identifier(name));
99        self.connection.execute(drop_sql.as_str(), None).await?;
100
101        // Evict the pool for the dropped database so stale connections
102        // are not reused.
103        self.connection.invalidate(name).await;
104
105        Ok(MessageResponse {
106            message: format!("Database '{name}' dropped successfully."),
107        })
108    }
109}
database_mcp_postgres/tools/drop_database.rs

database_mcp_postgres/tools/
drop_database.rs
