ios - Weird fatal error: unexpectedly found nil while unwrapping an Optional value -


i'm using sqlite ios swift app. below error snippet when select row database.

the problem is: has value generate fatal error. (unexpectedly found nil while unwrapping optional value)

enter image description here

the library used is: stephencelis/sqlite.swift

import foundation import sqlite  struct studentdb {     let table = table("students")     let code = expression<string>("code")     let name = expression<string>("name")     let gender = expression<int>("gender")     let birth = expression<string>("birth")     let born = expression<string>("born")     let classname = expression<string>("class")     let speciality = expression<string>("speciality")     let department = expression<string>("department")     let faculty = expression<string>("faculty")     let training = expression<string>("training")     let course = expression<string>("course")     let advisor = expression<string>("advisor") }  struct student {     let code: string!     let name: string?     let gender: int?     let birth: string?     let born: string?     let classname: string?     let speciality: string?     let department: string?     let faculty: string?     let training: string?     let course: string?     let advisor: string? }  class student {     class func getstudent(code: string) -> student? {         let studentdbinfo = studentdb()         let studentraw = try! userdatabase.pluck(studentdbinfo.table.filter(studentdbinfo.code == code))         if (studentraw != nil) {             let studentinfo = student(                 code: studentraw![studentdbinfo.code],                 name: studentraw![studentdbinfo.name],                 gender: studentraw![studentdbinfo.gender],                 birth: studentraw![studentdbinfo.birth],                 born: studentraw![studentdbinfo.born],                 classname: studentraw![studentdbinfo.classname],                 speciality: studentraw![studentdbinfo.speciality],                 department: studentraw![studentdbinfo.department],                 faculty: studentraw![studentdbinfo.faculty],                 training: studentraw![studentdbinfo.training],                 course: studentraw![studentdbinfo.course],                 advisor: studentraw![studentdbinfo.advisor]             )             return studentinfo         } else {             return nil         }     } }

all other column work fine. more clear:

print(studentraw![studentdbinfo.code]) -> crash  print(studentraw![studentdbinfo.name]) -> "pham tuan anh"

you force unwrapping studentraw, , that's crashing because it's nil. need add following before try use it.

guard let studentraw = studentraw else {     // handle error     return }

as why code has value, looks reusing variable, possibly has been set previously.


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