PostgreSQL for Swift

Prerequisites

The PostgreSQL C driver must be installed in order to use this package.
Follow the README of the cpostgresql repo to get started.

Using PostgreSQL

This section outlines how to import the PostgreSQL package both with or without a Vapor project.

With Vapor

The easiest way to use PostgreSQL with Vapor is to include the PostgreSQL provider.

import PackageDescription

let package = Package(
    name: "Project",
    dependencies: [
        .Package(url: "https://github.com/vapor/vapor.git", majorVersion: 2),
        .Package(url: "https://github.com/vapor-community/postgresql-provider.git", majorVersion: 2)
    ],
    exclude: [ ... ]
)

The PostgreSQL provider package adds PostgreSQL to your project and adds some additional, Vapor-specific conveniences like drop.postgresql().

Using import PostgreSQLProvider will import both Fluent and Fluent's Vapor-specific APIs.

With Fluent

Fluent is a powerful, pure-Swift ORM that can be used with any Server-Side Swift framework. The PostgreSQL driver allows you to use a PostgreSQL database to power your models and queries.

import PackageDescription

let package = Package(
    name: "Project",
    dependencies: [
        ...
        .Package(url: "https://github.com/vapor/fluent.git", majorVersion: 2),
        .Package(url: "https://github.com/vapor-community/postgresql-driver.git", majorVersion: 2)
    ],
    exclude: [ ... ]
)

Use import PostgreSQLDriver to access the PostgreSQLDriver class which you can use to initialize a Fluent Database.

Just PostgreSQL

At the core of the PostgreSQL provider and PostgreSQL driver is a Swift wrapper around the C PostgreSQL client. This package can be used by itself to send raw, parameterized queries to your PostgreSQL database.

import PackageDescription

let package = Package(
    name: "Project",
    dependencies: [
        ...
        .Package(url: "https://github.com/vapor/postgresql.git", majorVersion: 2)
    ],
    exclude: [ ... ]
)

Use import PostgreSQL to access the PostgreSQL.Database class.

Examples

Connecting to the Database

import PostgreSQL

let postgreSQL =  PostgreSQL.Database(
    hostname: "localhost",
    database: "test",
    user: "root",
    password: ""
)

Select

let version = try postgreSQL.execute("SELECT version()")

Prepared Statement

The second parameter to execute() is an array of PostgreSQL.Values.

let results = try postgreSQL.execute("SELECT * FROM users WHERE age >= $1", [.int(21)])

Listen and Notify

try postgreSQL.listen(to: "test_channel") { notification in
    print(notification.channel)
    print(notification.payload)
}

// Allow set up time for LISTEN
sleep(1)

try postgreSQL.notify(channel: "test_channel", payload: "test_payload")

Connection

Each call to execute() creates a new connection to the PostgreSQL database. This ensures thread safety since a single connection cannot be used on more than one thread.

If you would like to re-use a connection between calls to execute, create a reusable connection and pass it as the third parameter to execute().

let connection = try postgreSQL.makeConnection()
let result = try postgreSQL.execute("SELECT * FROM users WHERE age >= $1", [.int(21)]), connection)

Contributors

Maintained by Steven Roebert, Nate Bird, Prince Ugwuh, and other members of the Vapor community.