Rope

Rope provides a convenient, easy-to-use, type-safe access to PostgreSQL for server-side Swift 3.
It uses the thread-safe, highly performant libpq library.

Rope is so simple, you just need to learn 3 methods:

• connect() to create a connection
• query() to run a query
• rows() to turn a query result into a two-dimensional array

// credential struct as helper
let creds = RopeCredentials(host: "localhost", port: 5432,  dbName: "mydb",
                            user: "foo", password: "bar")

// establish connection using the struct, returns nil on error
guard let db = try? Rope.connect(credentials: creds) else {
	print("Could not connect to Postgres")
	return
}

// run INSERT query, it returns nil on a syntax or connection error
// the insert is SQL-injection safe due to the use of dollar params!
let text = "Hello World"
guard let _ = try? db.query("INSERT INTO my_table (my_text) VALUES($1)')", params: [text]) else {
	print("Could not insert \(text) into database");
	return
}

// run SELECT query, it returns nil on a syntax or connection error
guard let res = try? db.query("SELECT id, my_text FROM my_table") else {
	print("Could not fetch id & my_text from database")
	return
}

// execute statements with params (SQL-injection safe)  
guard let res = try? db.query("SELECT * FROM my_table WHERE my_text=$1", params: ["Hello World"]) else {
    print("Could not fetch id & my_text from database")
    return
}

// handle errors with a do/catch 
do {
    let res = try db.query("SELECT id, my_text FROM my_table")
} catch {
    // Error handling
}

// turn result into 2-dimensional array
if let rows = res?.rows() {
    for row in rows {
        let id = row["id"] as? Int
        let myText = row["my_text"] as? String
    }
}

• serial, bigserial, smallint, integer, and bigint are returned as Int
• real and double precision are returned as Float
• char, varchar, and text are returned as String
• json is converted to a Dictionary of [String: Any?]
• the boolean type is returned as Bool
• date, timestamp are returned as Date

Rope’s unit tests require a running Postgres 9.x database and you can either provide the database credentials via environment variables, or via CLI arguments or use the built-in default values.

All tests run without any additional configuration if your database has the following setup:

• host: "localhost"
• port: 5432
• database name: "rope"
• user: "postgres"
• password: ""

You can easily provide the database credentials via environment variables. Please see the RopeTestCredentials.swift file. Please also see the unit tests about how to use RopeCredentials to establish a connection.

For environment variables in Xcode, please enter the following info via Edit Scheme > Arguements using Environment Variables or Arguments Passend On Launch:

• DATABASE_HOST
• DATABASE_PORT
• DATABASE_NAME
• DATABASE_USER
• DATABASE_PASSWORD

swift build DATABASE_HOST=mydatabase_host DATABASE_PORT=mydatabase_port DATABASE_NAME=mydatabase_dbname DATABASE_USER=mydatabase_user DATABASE_PASSWORD=mydatabase_very_secure_password

To run tests simple type swift test in your CLI.

The source code is formatted using SwiftLint and all commits & PRs need to be without any SwiftLint warnings or errors.

Rope is maintained by Thomas Catterall (@swizzlr), Johannes Erhardt (@johanneserhardt), Sebastian Kreutzberger (@skreutzberger).

Contributions are more than welcomed. You can either work on existing Github issues or discuss with us your ideas in a new Github issue. Thanks 🙌

Rope is released under the Apache 2.0 License.