database_mcp_postgres/tools/
drop_table.rs

1//! MCP tool: `dropTable`.
2
3use std::borrow::Cow;
4
5use database_mcp_server::types::MessageResponse;
6use database_mcp_sql::Connection as _;
7use database_mcp_sql::SqlError;
8use database_mcp_sql::sanitize::{quote_ident, validate_ident};
9use rmcp::handler::server::router::tool::{AsyncTool, ToolBase};
10use rmcp::model::{ErrorData, ToolAnnotations};
11use sqlparser::dialect::PostgreSqlDialect;
12
13use crate::PostgresHandler;
14use crate::types::DropTableRequest;
15
16/// Marker type for the `dropTable` MCP tool.
17pub(crate) struct DropTableTool;
18
19impl DropTableTool {
20    const NAME: &'static str = "dropTable";
21    const TITLE: &'static str = "Drop Table";
22    const DESCRIPTION: &'static str = r#"Drop a table from a database. Checks for foreign key dependencies via the database engine.
23
24<usecase>
25Use when:
26- Removing a table that is no longer needed
27- Cleaning up test or temporary tables
28</usecase>
29
30<examples>
31✓ "Drop the temp_logs table" → dropTable(database="mydb", table="temp_logs")
32✓ "Force drop with dependencies" → dropTable(..., cascade=true)
33✗ "Delete rows from a table" → use writeQuery with DELETE
34✗ "Drop a database" → use dropDatabase instead
35</examples>
36
37<safety>
38IMPORTANT: This permanently deletes the table and ALL its data. This action cannot be undone.
39Set `cascade` to true to also drop dependent foreign key constraints.
40Without cascade, the drop will fail if other tables reference this one.
41</safety>
42
43<what_it_returns>
44A confirmation message with the dropped table name.
45</what_it_returns>"#;
46}
47
48impl ToolBase for DropTableTool {
49    type Parameter = DropTableRequest;
50    type Output = MessageResponse;
51    type Error = ErrorData;
52
53    fn name() -> Cow<'static, str> {
54        Self::NAME.into()
55    }
56
57    fn title() -> Option<String> {
58        Some(Self::TITLE.into())
59    }
60
61    fn description() -> Option<Cow<'static, str>> {
62        Some(Self::DESCRIPTION.into())
63    }
64
65    fn annotations() -> Option<ToolAnnotations> {
66        Some(
67            ToolAnnotations::new()
68                .read_only(false)
69                .destructive(true)
70                .idempotent(false)
71                .open_world(false),
72        )
73    }
74}
75
76impl AsyncTool<PostgresHandler> for DropTableTool {
77    async fn invoke(handler: &PostgresHandler, params: Self::Parameter) -> Result<Self::Output, Self::Error> {
78        Ok(handler.drop_table(params).await?)
79    }
80}
81
82impl PostgresHandler {
83    /// Drops a table from a database.
84    ///
85    /// Validates identifiers, then executes `DROP TABLE`. When `cascade`
86    /// is true the statement uses `CASCADE` to also remove dependent
87    /// foreign-key constraints.
88    ///
89    /// # Errors
90    ///
91    /// Returns [`SqlError::ReadOnlyViolation`] in read-only mode,
92    /// [`SqlError::InvalidIdentifier`] for invalid names,
93    /// or [`SqlError::Query`] if the backend reports an error.
94    pub async fn drop_table(
95        &self,
96        DropTableRequest {
97            database,
98            table,
99            cascade,
100        }: DropTableRequest,
101    ) -> Result<MessageResponse, SqlError> {
102        if self.config.read_only {
103            return Err(SqlError::ReadOnlyViolation);
104        }
105
106        validate_ident(&database)?;
107        validate_ident(&table)?;
108
109        let mut drop_sql = format!("DROP TABLE {}", quote_ident(&table, &PostgreSqlDialect {}));
110        if cascade {
111            drop_sql.push_str(" CASCADE");
112        }
113
114        self.connection.execute(drop_sql.as_str(), Some(&database)).await?;
115
116        Ok(MessageResponse {
117            message: format!("Table '{table}' dropped successfully."),
118        })
119    }
120}
database_mcp_postgres/tools/drop_table.rs

database_mcp_postgres/tools/
drop_table.rs
