dbmcp_postgres/tools/
create_database.rs

1//! MCP tool: `createDatabase`.
2
3use std::borrow::Cow;
4
5use dbmcp_server::types::{CreateDatabaseRequest, MessageResponse};
6use dbmcp_sql::Connection as _;
7use dbmcp_sql::SqlError;
8use rmcp::handler::server::router::tool::{AsyncTool, ToolBase};
9use rmcp::model::{ErrorData, ToolAnnotations};
10
11use crate::PostgresHandler;
12use crate::connection::quote_ident;
13
14/// Marker type for the `createDatabase` MCP tool.
15pub(crate) struct CreateDatabaseTool;
16
17impl CreateDatabaseTool {
18    const NAME: &'static str = "createDatabase";
19    const TITLE: &'static str = "Create Database";
20    const DESCRIPTION: &'static str = r#"Create a new database on the connected server.
21
22<usecase>
23Use when:
24- Setting up a new database for a project or application
25- The user asks to create a database
26</usecase>
27
28<examples>
29✓ "Create a database called analytics" → createDatabase(database="analytics")
30✗ "Create a table" → use writeQuery with CREATE TABLE
31</examples>
32
33<important>
34Database name must be non-empty; backend reserved-character rules apply.
35</important>
36
37<what_it_returns>
38A confirmation message with the created database name.
39</what_it_returns>"#;
40}
41
42impl ToolBase for CreateDatabaseTool {
43    type Parameter = CreateDatabaseRequest;
44    type Output = MessageResponse;
45    type Error = ErrorData;
46
47    fn name() -> Cow<'static, str> {
48        Self::NAME.into()
49    }
50
51    fn title() -> Option<String> {
52        Some(Self::TITLE.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(false)
64                .idempotent(false)
65                .open_world(false),
66        )
67    }
68}
69
70impl AsyncTool<PostgresHandler> for CreateDatabaseTool {
71    async fn invoke(handler: &PostgresHandler, params: Self::Parameter) -> Result<Self::Output, Self::Error> {
72        handler.create_database(params).await
73    }
74}
75
76impl PostgresHandler {
77    /// Creates a database if it doesn't exist.
78    ///
79    /// # Errors
80    ///
81    /// Returns [`SqlError`] if read-only or the query fails.
82    pub async fn create_database(
83        &self,
84        CreateDatabaseRequest { database }: CreateDatabaseRequest,
85    ) -> Result<MessageResponse, ErrorData> {
86        if self.config.read_only {
87            return Err(SqlError::ReadOnlyViolation.into());
88        }
89
90        let create_sql = format!("CREATE DATABASE {}", quote_ident(&database));
91        self.connection.execute(create_sql.as_str(), None).await.map_err(|e| {
92            let msg = e.to_string();
93            if msg.contains("already exists") {
94                return SqlError::Query(format!("Database '{database}' already exists."));
95            }
96            e
97        })?;
98
99        Ok(MessageResponse {
100            message: format!("Database '{database}' created successfully."),
101        })
102    }
103}
dbmcp_postgres/tools/create_database.rs

dbmcp_postgres/tools/
create_database.rs
