How to use “select * table where * = ?” in Swift with Sqlite3

Question

I'm using SQLlite3 for my database and i'm trying use "select * table where * = ?" in Swift with Sqlite3 but I'm stuck using where here's the method I used but i get no response from the methode .

    func DoesExist(titles: String?){

        ArticleList.removeAll()
        let queryStrings = "SELECT * FROM articles WHERE title = ? "
        var stmt3:OpaquePointer?
        if sqlite3_prepare(db, queryStrings, -1, &stmt3, nil) != SQLITE_OK{
            let errmsg = String(cString: sqlite3_errmsg(db)!)
            print("error preparing Select: \(errmsg)")
            return
        }
        if sqlite3_bind_text(stmt3, 1, titles, -1, nil) != SQLITE_OK{
            let errmsg = String(cString: sqlite3_errmsg(db)!)
            print("failure binding title: \(errmsg)")
            return
        }

        while(sqlite3_step(stmt3) == SQLITE_ROW){
            let id = sqlite3_column_int(stmt3, 0)
            let author = String(cString: sqlite3_column_text(stmt3, 1))
            let title = sqlite3_column_int(stmt3, 2)

            //adding values to list
            ArticleList.append(Article(id: Int(id), author: String(describing: author), title: String(describing: title)))
             print(ArticleList.count)
 }

    }

i don't know if that helps but when i try printing sqlite3_step(stmt3) i get 101 I don't get what I did wrong so if anyone is familiar with this error help, please?

*****UPDATE*****

i added

if sqlite3_step(stmt3) != SQLITE_DONE {
        let errmsg = String(cString: sqlite3_errmsg(db)!)
        print("failure inserting foo: \(errmsg)")
    }
    print("---------------------\(sqlite3_step(stmt3))")

and istead of getting 101 i got 21 which means : out of memory

Answer 1

The (admittedly misleading) “out of memory” error is SQLite's way of saying that the db pointer is nil . Print/test db before the sqlite3_xxx call that gave you the “out of memory” error, and you will see that it is, indeed, nil . If you are confident that you previously opened the database, then you must have some path of execution where you reset it to nil , or perhaps you have multiple db references floating about (eg some local var and the ivar).

You can add this test at the start of your method that has a precondition that the database must already be opened:

precondition(db != nil, "Database not open")