Struct edgedb_tokio::Transaction

pub struct Transaction { /* private fields */ }

Transaction object passed to the closure via Client::transaction() method

The Transaction object must be dropped by the end of the closure execution.

All database queries in transaction should be executed using methods on this object instead of using original Client instance.

Implementations

impl Transaction

pub fn iteration(&self) -> u32

Zero-based iteration (attempt) number for the current transaction

First attempt gets iteration = 0, second attempt iteration = 1, etc.

pub async fn query<R, A>( &mut self, query: &str, arguments: &A ) -> Result<Vec<R>, Error>where A: QueryArgs, R: QueryResult,

Execute a query and return a collection of results.

You will usually have to specify the return type for the query:

let greeting = pool.query::<String, _>("SELECT 'hello'", &());
// or
let greeting: Vec<String> = pool.query("SELECT 'hello'", &());

This method can be used with both static arguments, like a tuple of scalars, and with dynamic arguments edgedb_protocol::value::Value. Similarly, dynamically typed results are also supported.

pub async fn query_single<R, A>( &mut self, query: &str, arguments: &A ) -> Result<Option<R>, Error>where A: QueryArgs, R: QueryResult,

Execute a query and return a single result

You will usually have to specify the return type for the query:

let greeting = pool.query_single::<String, _>("SELECT 'hello'", &());
// or
let greeting: Option<String> = pool.query_single(
    "SELECT 'hello'",
    &()
);

This method can be used with both static arguments, like a tuple of scalars, and with dynamic arguments edgedb_protocol::value::Value. Similarly, dynamically typed results are also supported.

pub async fn query_required_single<R, A>( &mut self, query: &str, arguments: &A ) -> Result<R, Error>where A: QueryArgs, R: QueryResult,

Execute a query and return a single result

The query must return exactly one element. If the query returns more than one element, a ResultCardinalityMismatchError is raised. If the query returns an empty set, a NoDataError is raised.

You will usually have to specify the return type for the query:

let greeting = pool.query_required_single::<String, _>(
    "SELECT 'hello'",
    &(),
);
// or
let greeting: String = pool.query_required_single(
    "SELECT 'hello'",
    &(),
);

This method can be used with both static arguments, like a tuple of scalars, and with dynamic arguments edgedb_protocol::value::Value. Similarly, dynamically typed results are also supported.

pub async fn query_json( &mut self, query: &str, arguments: &impl QueryArgs ) -> Result<Json, Error>

Execute a query and return the result as JSON.

pub async fn query_single_json( &mut self, query: &str, arguments: &impl QueryArgs ) -> Result<Option<Json>, Error>

Execute a query and return a single result as JSON.

The query must return exactly one element. If the query returns more than one element, a ResultCardinalityMismatchError is raised.

pub async fn query_required_single_json( &mut self, query: &str, arguments: &impl QueryArgs ) -> Result<Json, Error>

Execute a query and return a single result as JSON.

The query must return exactly one element. If the query returns more than one element, a ResultCardinalityMismatchError is raised. If the query returns an empty set, a NoDataError is raised.

pub async fn execute<A>( &mut self, query: &str, arguments: &A ) -> Result<(), Error>where A: QueryArgs,

Execute a query and don’t expect result

This method can be used with both static arguments, like a tuple of scalars, and with dynamic arguments edgedb_protocol::value::Value. Similarly, dynamically typed results are also supported.

Trait Implementations

impl Debug for Transaction

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Drop for Transaction

fn drop(&mut self)

Executes the destructor for this type.