Trait Execute

pub trait Execute<'c, C>
where
    Self: Sized,
{
    type ExecuteOutput;
    type QueryOutput;

    // Required methods
    fn execute(self, cli: &'c C) -> Self::ExecuteOutput;
    fn query(self, cli: &'c C) -> Self::QueryOutput;
}

Defining how a query is executed. can be used for customizing encoding, executing and database data decoding.

For customized encoding please see Encode trait for detail. For customized decoding please see IntoResponse trait for detail.

when to use execute or query methods:

• execute method is for use case where sql produce an outcome where it only happen once. usually in the form of preparing a statement or observing how many rows have been modified.
• query method is for use case where sql produce repeated outcome where it can happen multiple times. usually in the form of visiting an iteration of database rows.

Required Associated Types

type ExecuteOutput

outcome of execute. used for single time database response: number of rows affected by execution for example.

type QueryOutput

outcome of query. used for repeated database response: database rows for example

consider impl AsyncLendingIterator for async iterator of rows consider impl Iterator for iterator of rows

for type of statement where no repeated response will returning this type can point to Execute::ExecuteOutput and it’s encouraged to make query behave identical to execute

Required Methods

fn execute(self, cli: &'c C) -> Self::ExecuteOutput

define how a statement is executed with single time response

fn query(self, cli: &'c C) -> Self::QueryOutput

define how a statement is queried with repeated response

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementations on Foreign Types

impl<'c, C> Execute<'c, C> for &Path

where C: Query + Sync + 'c,

type ExecuteOutput = Pin<Box<dyn Future<Output = Result<u64, Error>> + Send + 'c>>

type QueryOutput = Pin<Box<dyn Future<Output = Result<GenericRowStream<Vec<Column>, NoTyped>, Error>> + Send + 'c>>

fn execute(self, cli: &'c C) -> Self::ExecuteOutput

fn query(self, cli: &'c C) -> Self::QueryOutput

impl<'s, C> Execute<'_, C> for &'s str

where C: Query,

type ExecuteOutput = ResultFuture<RowAffected>

type QueryOutput = Ready<Result<GenericRowStream<Vec<Column>, NoTyped>, Error>>

fn execute(self, cli: &C) -> Self::ExecuteOutput

fn query(self, cli: &C) -> Self::QueryOutput

Implementors

impl<'c, C> Execute<'c, C> for StatementNamed<'_>

where C: Prepare + 'c,

type ExecuteOutput = ResultFuture<IntoGuarded<'c, Pin<Box<dyn Future<Output = Result<Statement, Error>> + Send + 'c>>, C>>

type QueryOutput = <StatementNamed<'_> as Execute<'c, C>>::ExecuteOutput

impl<'c, C, P> Execute<'c, C> for StatementUnnamedBind<'_, P>

where C: Prepare + 'c, P: AsParams,

type ExecuteOutput = ResultFuture<RowAffected>

type QueryOutput = Ready<Result<RowStreamGuarded<'c, C>, Error>>

impl<'p, C, B, const SYNC_MODE: bool> Execute<'_, C> for Pipeline<'p, B, SYNC_MODE>

where C: Query, B: DerefMut<Target = BytesMut>,

type ExecuteOutput = Pin<Box<dyn Future<Output = Result<u64, Error>> + Send + 'p>>

type QueryOutput = Result<PipelineStream<'p>, Error>

impl<'s, C> Execute<'_, C> for &'s Statement

where C: Query,

type ExecuteOutput = ResultFuture<RowAffected>

type QueryOutput = Ready<Result<GenericRowStream<&'s [Column], Typed>, Error>>

impl<'s, C, P> Execute<'_, C> for StatementQuery<'s, P>

where C: Query, P: AsParams,

type ExecuteOutput = ResultFuture<RowAffected>

type QueryOutput = Ready<Result<GenericRowStream<&'s [Column], Typed>, Error>>