database_mcp_postgres/tools/
create_database.rs

1//! MCP tool: `create_database`.
2
3use std::borrow::Cow;
4
5use database_mcp_server::AppError;
6use database_mcp_server::types::{CreateDatabaseRequest, MessageResponse};
7use database_mcp_sql::identifier::validate_identifier;
8use database_mcp_sql::timeout::execute_with_timeout;
9use rmcp::handler::server::router::tool::{AsyncTool, ToolBase};
10use rmcp::model::{ErrorData, ToolAnnotations};
11
12use crate::PostgresHandler;
13
14/// Marker type for the `create_database` MCP tool.
15pub(crate) struct CreateDatabaseTool;
16
17impl CreateDatabaseTool {
18    const NAME: &'static str = "create_database";
19    const DESCRIPTION: &'static str = "Create a new database.";
20}
21
22impl ToolBase for CreateDatabaseTool {
23    type Parameter = CreateDatabaseRequest;
24    type Output = MessageResponse;
25    type Error = ErrorData;
26
27    fn name() -> Cow<'static, str> {
28        Self::NAME.into()
29    }
30
31    fn description() -> Option<Cow<'static, str>> {
32        Some(Self::DESCRIPTION.into())
33    }
34
35    fn annotations() -> Option<ToolAnnotations> {
36        Some(
37            ToolAnnotations::new()
38                .read_only(false)
39                .destructive(false)
40                .idempotent(false)
41                .open_world(false),
42        )
43    }
44}
45
46impl AsyncTool<PostgresHandler> for CreateDatabaseTool {
47    async fn invoke(handler: &PostgresHandler, params: Self::Parameter) -> Result<Self::Output, Self::Error> {
48        Ok(handler.create_database(&params).await?)
49    }
50}
51
52impl PostgresHandler {
53    /// Creates a database if it doesn't exist.
54    ///
55    /// # Errors
56    ///
57    /// Returns [`AppError`] if read-only or the query fails.
58    pub async fn create_database(&self, request: &CreateDatabaseRequest) -> Result<MessageResponse, AppError> {
59        if self.config.read_only {
60            return Err(AppError::ReadOnlyViolation);
61        }
62        let name = &request.database_name;
63        validate_identifier(name)?;
64
65        let pool = self.get_pool(None).await?;
66
67        // PostgreSQL CREATE DATABASE can't use parameterized queries
68        let create_sql = format!("CREATE DATABASE {}", Self::quote_identifier(name));
69        execute_with_timeout(
70            self.config.query_timeout,
71            &create_sql,
72            sqlx::query(&create_sql).execute(&pool),
73        )
74        .await
75        .map_err(|e| {
76            let msg = e.to_string();
77            if msg.contains("already exists") {
78                return AppError::Query(format!("Database '{name}' already exists."));
79            }
80            e
81        })?;
82
83        Ok(MessageResponse {
84            message: format!("Database '{name}' created successfully."),
85        })
86    }
87}
database_mcp_postgres/tools/create_database.rs

database_mcp_postgres/tools/
create_database.rs
