executing raw queries vapor3 with fluent

raw-queries.swift

import Foundation
import FluentPostgreSQL
import Vapor

struct RemoveHashColumn: Migration {
    typealias Database = PostgreSQLDatabase

    static func prepare( on connection: PostgreSQLConnection ) -> Future<Void> {
        return Database.update(Files.self, on: connection) { builder in
            connection.raw("ALTER TABLE oldName RENAME TO newName;")
        }
    }

    static func revert(on connection: PostgreSQLConnection) -> EventLoopFuture<Void> {
        return Database.update(Files.self, on: connection) { builder in
            connection.raw("ALTER TABLE newName RENAME TO oldNew;")
        }
    }
}