database_mcp_postgres/tools/
drop_table.rs

1//! MCP tool: `drop_table`.
2
3use std::borrow::Cow;
4
5use database_mcp_server::AppError;
6use database_mcp_server::types::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;
13use crate::types::DropTableRequest;
14
15/// Marker type for the `drop_table` MCP tool.
16pub(crate) struct DropTableTool;
17
18impl DropTableTool {
19    const NAME: &'static str = "drop_table";
20    const DESCRIPTION: &'static str = r#"Drop a table from a database. Checks for foreign key dependencies via the database engine.
21
22<usecase>
23Use when:
24- Removing a table that is no longer needed
25- Cleaning up test or temporary tables
26</usecase>
27
28<examples>
29✓ "Drop the temp_logs table" → drop_table(database_name="mydb", table_name="temp_logs")
30✓ "Force drop with dependencies" → drop_table(..., cascade=true)
31✗ "Delete rows from a table" → use write_query with DELETE
32✗ "Drop a database" → use drop_database instead
33</examples>
34
35<safety>
36IMPORTANT: This permanently deletes the table and ALL its data. This action cannot be undone.
37Set `cascade` to true to also drop dependent foreign key constraints.
38Without cascade, the drop will fail if other tables reference this one.
39</safety>
40
41<what_it_returns>
42A confirmation message with the dropped table name.
43</what_it_returns>"#;
44}
45
46impl ToolBase for DropTableTool {
47    type Parameter = DropTableRequest;
48    type Output = MessageResponse;
49    type Error = ErrorData;
50
51    fn name() -> Cow<'static, str> {
52        Self::NAME.into()
53    }
54
55    fn description() -> Option<Cow<'static, str>> {
56        Some(Self::DESCRIPTION.into())
57    }
58
59    fn annotations() -> Option<ToolAnnotations> {
60        Some(
61            ToolAnnotations::new()
62                .read_only(false)
63                .destructive(true)
64                .idempotent(false)
65                .open_world(false),
66        )
67    }
68}
69
70impl AsyncTool<PostgresHandler> for DropTableTool {
71    async fn invoke(handler: &PostgresHandler, params: Self::Parameter) -> Result<Self::Output, Self::Error> {
72        Ok(handler.drop_table(&params).await?)
73    }
74}
75
76impl PostgresHandler {
77    /// Drops a table from a database.
78    ///
79    /// Validates identifiers, then executes `DROP TABLE`. When `cascade`
80    /// is true the statement uses `CASCADE` to also remove dependent
81    /// foreign-key constraints.
82    ///
83    /// # Errors
84    ///
85    /// Returns [`AppError::ReadOnlyViolation`] in read-only mode,
86    /// [`AppError::InvalidIdentifier`] for invalid names,
87    /// or [`AppError::Query`] if the backend reports an error.
88    pub async fn drop_table(&self, request: &DropTableRequest) -> Result<MessageResponse, AppError> {
89        if self.config.read_only {
90            return Err(AppError::ReadOnlyViolation);
91        }
92        let database = &request.database_name;
93        let table = &request.table_name;
94        validate_identifier(database)?;
95        validate_identifier(table)?;
96
97        let mut drop_sql = format!("DROP TABLE {}", self.connection.quote_identifier(table));
98        if request.cascade {
99            drop_sql.push_str(" CASCADE");
100        }
101
102        self.connection.execute(drop_sql.as_str(), Some(database)).await?;
103
104        Ok(MessageResponse {
105            message: format!("Table '{table}' dropped successfully."),
106        })
107    }
108}
database_mcp_postgres/tools/drop_table.rs

database_mcp_postgres/tools/
drop_table.rs
