Cannot make Connection to SQLite database Swift 3 -

i'm using sqlite library , in usage says let db = try connection("path/to/db.sqlite3") have sqlite database located in documents. when try make connection throw error call can throw errors cannot thrown out of property initializer

here's code :

import uikit import sqlite  class searchviewcontroller: uiviewcontroller, uitextfielddelegate {  let db = try connection("/users/macbookpro/documents/db.sqlite") //error let categoryvc = categoryviewcontroller() let usefullvc = usefullviewcontroller() let mapvc = mapviewcontroller() let eventvc = searchresultonlinevc()  @iboutlet weak var searchtextfield: uitextfield!  override func viewdidload() {     super.viewdidload()      self.title = "search"      searchtextfield.delegate = self }  override func didreceivememorywarning() {     super.didreceivememorywarning() } } 

i try put connection in viewdidload still doesn't work

what's wrong?

since connection initializer can throw exception, need call in do/catch block.

so should change declaration to:

var db : connection? 

and initialize in viewdidload:

do{     self.db = try connection("/users/macbookpro/documents/db.sqlite") } catch {     print("unable create connection: \(error)") }