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iossqlite.swiftgrdb

Converting app from SQLite.swift to GRDB.swift


I'm trying to convert several of my apps to use GRDB.swift. Does anybody have or know where I can find a file to get me started? I've read over most of the GRDB docs but I'm not getting it. Below is a sample scenario.

This I was able to convert from SQLite.sift

class Database
{
    static let shared = Database()
    public let databaseConnection: DatabaseQueue?
    
    private init()
    {
        do
        {
            let fileUrl = try FileManager.default.url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: false).appendingPathComponent("MyDaatbase.sqlite")
            
            // GRDB
            let databaseConnection = try DatabaseQueue(path: fileUrl.path)
            self.databaseConnection = databaseConnection
        } catch {
            databaseConnection = nil
            let nserror = error as NSError
            print("Cannot connect to Database. Error is: \(nserror), \(nserror.userInfo)")
        }
    }
}

Could someone please convert this to GRDB to help me get started?

static func isAnimation() -> Bool
    {
        let theTable = Table("Settings")
        let theColumn = Expression<String>("AnimateNav")
        var theStatus = false
        
        do {
            for theAnswer in try Database.shared.databaseConnection!.prepare(theTable.select(theColumn)) {
                //print(theAnswer[theColumn])
                let theStatusText = (theAnswer[theColumn])
                
                theStatus = theStatusText == "true" ? true : false
            }
        } catch {
            print("Getting the isAnimation Status failed! Error: \(error)")
        }
        return theStatus
    }

Solution

  • You can use raw SQL:

    static func isAnimation() -> Bool {
        var theStatus = false
        do {
            let animateNav = try Database.shared.databaseConnection!.read { db in
                String.fetchOne(db, sql: "SELECT AnimateNav FROM Settings")
            }
            theStatus = animateNav == "true" ? true : false
        } catch {
            print("Getting the isAnimation Status failed! Error: \(error)")
        }
        return theStatus
    }
    

    You can also define a Record type for the Settings table, which is the preferred GRDB way:

    // Settings.swift
    struct Settings: Codable, FetchableRecord, TableRecord {
        var animateNav: String
        // other properties for other columns in the Settings table
        ...
    }
    
    // Your file
    static func isAnimation() -> Bool {
        var theStatus = false
        do {
            let settings = try Database.shared.databaseConnection!.read { db in
                try Settings.fetchOne(db)
            }
            theStatus = settings?.animateNav == "true" ? true : false
        } catch {
            print("Getting the isAnimation Status failed! Error: \(error)")
        }
        return theStatus
    }