Struct Connection

pub struct Connection { /* private fields */ }

An asynchronous connection to the database.

Implementations

impl Connection

pub async fn new<P>(params: P) -> Result<Connection, HdbError>

where P: IntoConnectParams,

Factory method for authenticated connections.

See ConnectParams, ConnectParamsBuilder, and IntoConnectParams for the available options of providing the input to this function.

Example

use hdbconnect_async::Connection;
let mut conn = Connection::new("hdbsql://my_user:my_passwd@the_host:2222").await.unwrap();

Errors

Several variants of HdbError can occur.

pub async fn with_configuration<P>( params: P, config: &ConnectionConfiguration, ) -> Result<Connection, HdbError>

where P: IntoConnectParams,

Factory method for authenticated connections with given configuration.

Errors

Several variants of HdbError can occur.

pub async fn statement<S>(&self, stmt: S) -> Result<HdbResponse, HdbError>

where S: AsRef<str>,

Executes a statement on the database.

This generic method can handle all kinds of calls, and thus has the most generic return type. In many cases it will be more convenient to use one of the dedicated methods query(), dml(), exec() below, which internally convert the HdbResponse to the respective adequate simple result type.

Example

let mut response = connection.statement(&statement_string).await.unwrap(); // HdbResponse

Errors

Several variants of HdbError can occur.

pub async fn query<S>(&self, stmt: S) -> Result<ResultSet, HdbError>

where S: AsRef<str>,

Executes a statement and expects a single ResultSet.

Should be used for query statements (like “SELECT …”) which return a single result set.

Example

let mut rs = connection.query(&statement_string).await.unwrap(); // ResultSet

Errors

Several variants of HdbError can occur.

pub async fn dml<S>(&self, stmt: S) -> Result<usize, HdbError>

where S: AsRef<str>,

Executes a statement and expects a single number of affected rows.

Should be used for DML statements only, i.e., INSERT, UPDATE, DELETE, UPSERT.

Example

let count = connection.dml(&statement_string).await.unwrap(); //usize

Errors

Several variants of HdbError can occur.

pub async fn exec<S>(&self, stmt: S) -> Result<(), HdbError>

where S: AsRef<str>,

Executes a statement and expects a plain success.

Should be used for SQL commands like “ALTER SYSTEM …”.

Example

connection.exec(&statement_string).await.unwrap();

Errors

Several variants of HdbError can occur.

pub async fn prepare<S>(&self, stmt: S) -> Result<PreparedStatement, HdbError>

where S: AsRef<str>,

Prepares a statement and returns a handle (a PreparedStatement) to it.

Note that the PreparedStatement keeps using the same database connection as this Connection.

Example

let query_string = "select * from phrases where ID = ? and text = ?";
let mut statement = connection.prepare(query_string).await.unwrap(); //PreparedStatement

Errors

Several variants of HdbError can occur.

pub async fn prepare_and_execute<S, T>( &self, stmt: S, input: &T, ) -> Result<HdbResponse, HdbError>

where S: AsRef<str>, T: Serialize,

Prepares a statement and executes it a single time.

Errors

Several variants of HdbError can occur.

pub async fn commit(&self) -> Result<(), HdbError>

Commits the current transaction.

Errors

Several variants of HdbError can occur.

pub async fn rollback(&self) -> Result<(), HdbError>

Rolls back the current transaction.

Errors

Several variants of HdbError can occur.

pub async fn spawn(&self) -> Result<Connection, HdbError>

Creates a new connection object with the same settings and authentication.

Errors

Several variants of HdbError can occur.

pub async fn multiple_statements_ignore_err<S>(&self, stmts: Vec<S>)

where S: AsRef<str>,

Utility method to fire a couple of statements, ignoring errors and return values.

Errors

Several variants of HdbError can occur.

pub async fn multiple_statements<S>( &self, stmts: Vec<S>, ) -> Result<(), HdbError>

where S: AsRef<str>,

Utility method to fire a couple of statements, ignoring their return values; the method returns with the first error, or with ().

Errors

Several variants of HdbError can occur.

pub async fn pop_warnings(&self) -> Option<Vec<ServerError>>

Returns warnings that were returned from the server since the last call to this method.

pub async fn set_auto_commit(&self, ac: bool)

Sets the connection’s auto-commit behavior.

pub async fn is_auto_commit(&self) -> bool

Returns the connection’s auto-commit behavior.

pub async fn set_cursor_holdability( &self, holdability: CursorHoldability, ) -> Result<(), HdbError>

Sets the connection’s cursor holdability.

Errors

Only HdbError::Poison can occur.

pub async fn cursor_holdability(&self) -> Result<CursorHoldability, HdbError>

Returns the connection’s cursor holdability.

Errors

Only HdbError::Poison can occur.

pub async fn fetch_size(&self) -> u32

Returns the connection’s fetch size.

pub async fn set_fetch_size(&self, fetch_size: u32)

Configures the connection’s fetch size.

pub async fn read_timeout(&self) -> Result<Option<Duration>, HdbError>

Returns the connection’s read timeout.

Errors

Various errors can occur.

pub async fn set_read_timeout( &self, read_timeout: Option<Duration>, ) -> Result<(), HdbError>

Sets the connection’s read timeout.

Errors

Various errors can occur.

pub async fn lob_read_length(&self) -> u32

Returns the connection’s lob read length.

pub async fn set_lob_read_length(&self, l: u32)

Configures the connection’s lob read length.

Errors

Only HdbError::Poison can occur.

pub async fn lob_write_length(&self) -> u32

Returns the connection’s lob write length.

pub async fn set_lob_write_length(&self, l: u32)

Sets the connection’s lob write length.

The intention of the parameter is to allow reducing the number of roundtrips to the database.

pub async fn set_max_buffer_size(&mut self, max_buffer_size: usize)

Sets the connection’s maximum buffer size.

See also ConnectionConfiguration::set_max_buffer_size.

pub async fn id(&self) -> u32

Returns the ID of the connection.

The ID is set by the server. Can be handy for logging.

pub async fn server_usage(&self) -> ServerUsage

Provides information about the the server-side resource consumption that is related to this Connection object.

pub async fn statistics(&self) -> ConnectionStatistics

Returns some statistics snapshot about what was done with this connection so far.

pub async fn reset_statistics(&self)

Reset the counters in the Connection’s statistic object.

pub async fn set_application<S>(&self, application: S)

where S: AsRef<str>,

Sets client information into a session variable on the server.

Example:

connection.set_application("MyApp, built in rust").await;

pub async fn set_application_user<S>(&self, appl_user: S)

where S: AsRef<str>,

Sets client information into a session variable on the server.

Example:

connection.set_application_user("K2209657").await;

pub async fn set_application_version<S>(&self, version: S)

where S: AsRef<str>,

Sets client information into a session variable on the server.

Example:

connection.set_application_version("5.3.23").await.unwrap();

pub async fn set_application_source<S>(&self, source: S)

where S: AsRef<str>,

Sets client information into a session variable on the server.

Example:

connection.set_application_source("update_customer.rs").await.unwrap();

pub fn get_resource_manager(&self) -> Box<dyn ResourceManager>

Returns an implementation of dist_tx_async::rm::ResourceManager that is based on this connection.

pub async fn execute_with_debuginfo<S>( &mut self, stmt: S, module: S, line: u32, ) -> Result<HdbResponse, HdbError>

where S: AsRef<str>,

Tools like debuggers can provide additional information while stepping through a source.

Errors

Several variants of HdbError can occur.

pub async fn get_database_name(&self) -> String

(MDC) Database name.

pub async fn get_system_id(&self) -> String

The system id is set by the server with the SAPSYSTEMNAME of the connected instance (for tracing and supportability purposes).

pub async fn client_info(&self) -> Vec<(String, String)>

Returns the information that is given to the server as client context.

pub async fn connect_string(&self) -> String

Returns a connect url (excluding the password) that reflects the options that were used to establish this connection.

pub async fn get_full_version_string(&self) -> String

HANA Full version string.

Errors

Errors are unlikely to occur.

• HdbErr::Impl if the version string was not provided by the database server.
• HdbError::Poison if the shared mutex of the inner connection object is poisened.

pub async fn is_broken(&self) -> bool

Returns true if the connection object lost its TCP connection.

Trait Implementations

impl Clone for Connection

fn clone(&self) -> Connection

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Connection

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

Formats the value using the given formatter.