Reactive Relational Database Connectivity PostgreSQL Implementation

This project contains the PostgreSQL implementation of the R2DBC SPI. This implementation is not intended to be used directly, but rather to be used as the backing implementation for a humane client library to delegate to.

This driver provides the following features:

• Login with username/password or implicit trust
• Explict transactions
• Execution of prepared statements with bindings
• Execution of batch statements without bindings
• Read and write support for all data types except LOB types (e.g. BLOB, CLOB)

Next steps:

• TLS
• Multi-dimensional arrays
• Notifications
• SCRAM authentication
• Binary data transfer

Maven

Both milestone and snapshot artifacts (library, source, and javadoc) can be found in Maven repositories.

<dependency>
  <groupId>io.r2dbc</groupId>
  <artifactId>r2dbc-postgresql</artifactId>
  <version>1.0.0.M7</version>
</dependency>

Artifacts can be found at the following repositories.

Repositories

<repository>
    <id>spring-snapshots</id>
    <name>Spring Snapshots</name>
    <url>https://repo.spring.io/snapshot</url>
    <snapshots>
        <enabled>true</enabled>
    </snapshots>
</repository>

<repository>
    <id>spring-milestones</id>
    <name>Spring Milestones</name>
    <url>https://repo.spring.io/milestone</url>
    <snapshots>
        <enabled>false</enabled>
    </snapshots>
</repository>

Usage

Configuration of the ConnectionFactory can be accomplished in two ways:

Connection Factory Discovery

ConnectionFactory connectionFactory = ConnectionFactories.get(ConnectionFactoryOptions.builder()
   .option(DRIVER, "postgresql")
   .option(HOST, "...")
   .option(PORT, "...")  // optional, defaults to 5432
   .option(USER, "...")
   .option(PASSWORD, "...")
   .option(DATABASE, "...")  // optional
   .build());

Publisher<? extends Connection> connectionPublisher = connectionFactory.create();

// Alternative: Creating a Mono using Project Reactor
Mono<Connection> connectionMono = Mono.from(connectionFactory.create());

Supported Connection Factory Discovery options:

Programmatic

ConnectionFactory connectionFactory = new PostgresqlConnectionFactory(PostgresqlConnectionConfiguration.builder()
    .host("...")
    .port("...").  // optional, defaults to 5432
    .username("...")
    .password("...")
    .database("...")  // optional
    .build());

Mono<Connection> mono = connectionFactory.create();

PostgreSQL uses index parameters that are prefixed with $. The following SQL statement makes use of parameters:

INSERT INTO person (id, first_name, last_name) VALUES ($1, $2, $3)

Parameters are referenced using the same identifiers when binding these:

mono.flatMapMany(connection -> connection
                .createStatement("INSERT INTO person (id, first_name, last_name) VALUES ($1, $2, $3)")
                .bind("$1", 1)
                .bind("$2", "Walter")
                .bind("$3", "White")
                .execute());

Binding also allowed positional index (zero-based) references. The parameter index is derived from the parameter discovery order when parsing the query.

Data Type Mapping

This reference table shows the type mapping between PostgreSQL and Java data types:

Types in bold indicate the native (default) Java type.

Support for the following single-dimensional arrays (read and write):

License

This project is released under version 2.0 of the Apache License.