Struct Client

Source

pub struct Client { /* private fields */ }

Expand description

EdgeDB Client

Internally it contains a connection pool.

To create client, use create_client function.

Implementations§

Source §

impl Client

Source

pub fn query<R, A>(&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.

Source

pub fn query_single<R, A>( &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.

Source

pub fn query_required_single<R, A>( &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.

Source

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

Execute a query and return the result as JSON.

Source

pub fn query_single_json( &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.

Source

pub fn query_required_single_json( &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.

Source

pub fn transaction<T, F>(&self, body: F) -> Result<T, Error>
where F: FnMut(&mut Transaction) -> Result<T, Error>,

Execute a transaction

Transaction body must be encompassed in the closure. The closure may be executed multiple times. This includes not only database queries but also executing the whole function, so the transaction code must be prepared to be idempotent.

§Example

let conn = edgedb_sdk::client::create_client();
let val = conn.transaction(|mut tx| {
    // TODO(tailhook) query_required_single
    tx.query_required_single::<i64, _>("
        WITH C := UPDATE Counter SET { value := .value + 1}
        SELECT C.value LIMIT 1
    ", &()
    )
})?;