Struct PgConnection

pub struct PgConnection { /* private fields */ }

A connection to a PostgreSQL database.

Implementations

impl PgConnection

pub fn wait_until_ready(&mut self) -> Result<(), Error>

impl PgConnection

pub fn copy_in_raw(&mut self, statement: &str) -> Result<PgCopyIn<&mut Self>>

Issue a COPY FROM STDIN statement and transition the connection to streaming data to Postgres. This is a more efficient way to import data into Postgres as compared to INSERT but requires one of a few specific data formats (text/CSV/binary).

If statement is anything other than a COPY ... FROM STDIN ... command, an error is returned.

Command examples and accepted formats for COPY data are shown here: https://www.postgresql.org/docs/current/sql-copy.html

Note

PgCopyIn::finish or PgCopyIn::abort must be called when finished or the connection will return an error the next time it is used.

pub fn copy_out_raw<'c>( &'c mut self, statement: &str, ) -> Result<ChanStream<Bytes>>

Issue a COPY TO STDOUT statement and transition the connection to streaming data from Postgres. This is a more efficient way to export data from Postgres but arrives in chunks of one of a few data formats (text/CSV/binary).

If statement is anything other than a COPY ... TO STDOUT ... command, an error is returned.

Note that once this process has begun, unless you read the stream to completion, it can only be canceled in two ways:

1. by closing the connection, or:
2. by using another connection to kill the server process that is sending the data as shown in this StackOverflow answer.

If you don’t read the stream to completion, the next time the connection is used it will need to read and discard all the remaining queued data, which could take some time.

Command examples and accepted formats for COPY data are shown here: https://www.postgresql.org/docs/current/sql-copy.html

Trait Implementations

impl Connection for PgConnection

type Options = PgConnectOptions

fn close(self) -> Result<(), Error>

Explicitly close this database connection.

fn ping(&mut self) -> Result<(), Error>

Checks if a connection to the database is still valid.

fn begin(&mut self) -> Result<Transaction<'_, Self::Database>, Error>

where Self: Sized,

Begin a new transaction or establish a savepoint within the active transaction.

fn cached_statements_size(&self) -> usize

The number of statements currently cached in the connection.

fn clear_cached_statements(&mut self) -> Result<(), Error>

Removes all statements from the cache, closing them on the server if needed.

fn transaction<'a, F, R, E>(&'a mut self, callback: F) -> Result<R, E>

where F: for<'c> FnOnce(&'c mut Transaction<'_, Self::Database>) -> Result<R, E> + 'a + for<'c> Send + for<'c> Sync, Self: Sized, R: Send, E: From<Error> + Send,

Execute the function inside a transaction.

fn connect(url: &str) -> Result<Self, Error>

where Self: Sized,

Establish a new database connection.

fn connect_with(options: &Self::Options) -> Result<Self, Error>

where Self: Sized,

Establish a new database connection with the provided options.

impl Debug for PgConnection

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

Formats the value using the given formatter.

impl Executor for &mut PgConnection

type Database = Postgres

fn fetch_many<'q, E>( &mut self, query: E, ) -> ChanStream<Either<<Self::Database as Database>::QueryResult, <Self::Database as Database>::Row>>

where E: Execute<'q, Self::Database> + 'q,

Execute multiple queries and return the generated results as a stream from each query, in a stream.

fn fetch_optional<'q, E>( &mut self, query: E, ) -> Result<Option<<Self::Database as Database>::Row>, Error>

where E: Execute<'q, Self::Database> + 'q,

Execute the query and returns at most one row.

fn prepare_with<'q>( &mut self, sql: &'q str, parameters: &'q [<Self::Database as Database>::TypeInfo], ) -> Result<<Self::Database as HasStatement>::Statement, Error>

Prepare the SQL query, with parameter type information, to inspect the type information about its parameters and results.

fn execute<'q, E>( &mut self, query: E, ) -> Result<<Self::Database as Database>::QueryResult, Error>

where E: 'q + Execute<'q, Self::Database>,

Execute the query and return the total number of rows affected.

fn execute_many<'q, E>( &mut self, query: E, ) -> ChanStream<<Self::Database as Database>::QueryResult>

where E: 'q + Execute<'q, Self::Database>,

Execute multiple queries and return the rows affected from each query, in a stream.

fn fetch<'q, E>( &mut self, query: E, ) -> ChanStream<<Self::Database as Database>::Row>

where E: 'q + Execute<'q, Self::Database>,

Execute the query and return the generated results as a stream.

fn fetch_all<'q, E>( &mut self, query: E, ) -> Result<Vec<<Self::Database as Database>::Row>, Error>

where E: 'q + Execute<'q, Self::Database>,

Execute the query and return all the generated results, collected into a Vec.

fn fetch_one<'q, E>( &mut self, query: E, ) -> Result<<Self::Database as Database>::Row, Error>

where E: 'q + Execute<'q, Self::Database>,

Execute the query and returns exactly one row.

fn prepare<'q>( &mut self, query: &'q str, ) -> Result<<Self::Database as HasStatement>::Statement, Error>

Prepare the SQL query to inspect the type information of its parameters and results.

impl Executor for PgConnection

type Database = Postgres

fn fetch_many<'q, E>( &mut self, query: E, ) -> ChanStream<Either<PgQueryResult, PgRow>>

where E: Execute<'q, Self::Database> + 'q,

Execute multiple queries and return the generated results as a stream from each query, in a stream.

fn fetch_optional<'q, E>(&mut self, query: E) -> Result<Option<PgRow>, Error>

where E: Execute<'q, Self::Database> + 'q,

Execute the query and returns at most one row.

fn prepare_with<'q>( &mut self, sql: &'q str, parameters: &'q [PgTypeInfo], ) -> Result<PgStatement, Error>

Prepare the SQL query, with parameter type information, to inspect the type information about its parameters and results.

fn execute<'q, E>( &mut self, query: E, ) -> Result<<Self::Database as Database>::QueryResult, Error>

where E: 'q + Execute<'q, Self::Database>,

Execute the query and return the total number of rows affected.

fn execute_many<'q, E>( &mut self, query: E, ) -> ChanStream<<Self::Database as Database>::QueryResult>

where E: 'q + Execute<'q, Self::Database>,

Execute multiple queries and return the rows affected from each query, in a stream.

fn fetch<'q, E>( &mut self, query: E, ) -> ChanStream<<Self::Database as Database>::Row>

where E: 'q + Execute<'q, Self::Database>,

Execute the query and return the generated results as a stream.

fn fetch_all<'q, E>( &mut self, query: E, ) -> Result<Vec<<Self::Database as Database>::Row>, Error>

where E: 'q + Execute<'q, Self::Database>,

Execute the query and return all the generated results, collected into a Vec.

fn fetch_one<'q, E>( &mut self, query: E, ) -> Result<<Self::Database as Database>::Row, Error>

where E: 'q + Execute<'q, Self::Database>,

Execute the query and returns exactly one row.

fn prepare<'q>( &mut self, query: &'q str, ) -> Result<<Self::Database as HasStatement>::Statement, Error>

Prepare the SQL query to inspect the type information of its parameters and results.

impl<'c> From<&'c mut PgConnection> for MaybePoolConnection<'c, Postgres>

fn from(v: &'c mut PgConnection) -> Self

Converts to this type from the input type.

impl PgConnectionInfo for PgConnection

fn server_version_num(&self) -> Option<u32>

the version number of the server in libpq format