Struct Query 

pub struct Query<'a> { /* private fields */ }

A prepared query returning untyped crate::Rows.

Implementations

impl<'a> Query<'a>

pub fn new(sql: &'a str, params: &'a [&'a dyn ToSql]) -> Self

Builds a query from SQL and already-built parameters.

pub async fn execute<E: Executor>(&self, executor: &E) -> Result<u64, Error>

Runs the statement and returns the number of affected rows.

Use this for statements that change data (INSERT, UPDATE, DELETE, DDL). Any rows the statement produces are read and discarded; the returned count is the command tag’s affected-row count (for example the number of inserted or updated rows).

Errors

Returns a server error if the statement fails, or Error::Closed if the connection is gone.

pub async fn fetch_rows<E: Executor>( &self, executor: &E, ) -> Result<RowStream, Error>

Runs the statement and returns a stream of rows.

pub async fn fetch_all<E: Executor, T: FromRow>( &self, executor: &E, ) -> Result<Vec<T>, Error>

Collects all rows into a Vec<T>.

The result is unbounded: use Query::fetch_rows to process a large result without holding it all in memory.

pub async fn fetch_one<E: Executor, T: FromRow>( &self, executor: &E, ) -> Result<T, Error>

Returns exactly one row, or Error::RowNotFound.

pub async fn fetch_optional<E: Executor, T: FromRow>( &self, executor: &E, ) -> Result<Option<T>, Error>

Returns the first row, if any.