Raku Land

Net::Postgres

cpan:LEONT

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Name

Net::Postgres - an asynchronous postgresql client

Synopsis

use v6.d;
use Net::Postgres;

my $client = await Net::Postgres::Connection.connect-tcp(:$host, :$port, :$user, :$password, :$database, :$tls);

my $resultset = await $client.query('SELECT * FROM foo WHERE id = $1', 42);
for $resultset.hashes -> (:$name, :$description) {
    say "$name is $description";
}

Description

Net::Postgres is asynchronous implementation of (the client side of) the postgresql protocol based on Protocol::Postgres. It is typically used through the Net::Postgres::Client class.

Client

Net::Postgres::Client has the following methods

new(--> Protocol::Postgres::Client)

This creates a new postgres client. It takes the following named arguments:

* Str :$host = 'localhost'

* Int :$port = 5432

* Str :$user = ~$*USER

* Str :password

* Str :$database

* TypeMap :$typemap = Protocol::Postgres::TypeMap::Simple

* Bool :$tls = False

if $tls is enabled, it will pass on all unknown named arguments to IO::Socket::Async::SSL.

query($query, @bind-values --> Promise)

This will issue a query with the given bind values, and return a promise to the result.

For fetching queries such as SELECT the result in the promise will be a ResultSet object, for manipulation (e.g. INSERT) and definition (e.g. CREATE) queries it will result a string describing the change (e.g. DELETE 3). For a COPY TO query it will Supply with the data stream, and for COPY FROM it will be a Supplier.

Both the input types and the output types will be typemapped between Raku types and Postgres types using the typemapper.

query-multiple($query --> Supply[ResultSet])

This will issue a complex query that may contain multiple statements, but can not use bind values. It will return a Supply to the results of each query.

prepare($query --> Promise[PreparedStatement])

This prepares the query, and returns a Promise to the PreparedStatement object.

terminate(--> Nil)

This sends a message to the server to terminate the connection

listen(Str $channel-name --> Promise[Supply])

This listens to notifications on the given channel. It returns a Promise to a Supply of Notifications.

ResultSet

A Net::Postgres::ResultSet represents the results of a query, if any. It defines the following methods:

columns(--> List)

This returns the column names for this resultset.

rows(--> Supply[List])

This returns a Supply of rows. Each row is a list of values.

hash-rows(--> Supply[Hash])

This returns a Supply of rows. Each row is a hash with the column names as keys and the row values as values.

arrays

This returns a sequence of arrays of results from all rows. This may await.

array

This returns a single array of results from one row. This may await.

value

This returns a single value from a single row. This may await.

hashes

This returns a sequence of hashes of the results from all rows. This may await.

hash

This returns a single hash of the results from one rows. This may await.

PreparedStatement

A Net::Postgres::PreparedStatement represents a prepated statement. Its reason of existence is to call execute on it.

execute(@arguments --> Promise)

This runs the prepared statement, much like the query method would have done and with the same result values.

close()

This closes the prepared statement.

columns()

This returns the columns of the result once executed.

Notification

Net::Postgres::Notification has the following methods:

sender(--> Int)

This is the process-id of the sender

message(--> Str)

This is the message of the notification

Todo

Author

Leon Timmermans fawaka@gmail.com

Copyright and License

Copyright 2022 Leon Timmermans

This library is free software; you can redistribute it and/or modify it under the Artistic License 2.0.