Vapor3 PostgreSQL extension to decode [[PostgreSQLColumn: PostgreSQLData]] with Codable struct

PostgreSQLQueryCodableExample.swift

import PostgreSQL

typealias PostgreSQLQueryRow = [PostgreSQLColumn: PostgreSQLData]

extension Dictionary where Key == PostgreSQLColumn, Value == PostgreSQLData {
    func decode<T>(_ key: String) throws -> T where T: PostgreSQLDataConvertible {
        guard let v = try firstValue(forColumn: key)?.decode(T.self) else {
            throw PostgreSQLError(identifier: "decodingError", reason: "Unable to decode \"\(key)\" column ", source: .capture())
        }
        return v
    }
}

//Example usage

struct User: Content {
    var id: UUID
    var name: String
    var email: String
        
    init (_ queryData: PostgreSQLQueryRow) throws {
        id = try queryData.decode( "id")
        name = try queryData.decode("name")
        email = try queryData.decode("email")
    }
}

func someEndpoint(_ req: Request) throws -> Future<[User]> {
    return req.requestPooledConnection(to: .psql).flatMap { conn -> EventLoopFuture<[User]> in
        return conn.query("SELECT id, name, email FROM \"Users\"").map { queryResult -> [User] in
            return try queryResult.map { try User($0) }
        }
    }
}