Can't store data between app launches

[gerchicov-vg]

Creating table works, inserting data works, migrating possibly works too but I don't understand how to persist these changes.
Tried examples from this repo - CaseStudies work only but it says to use SwiftUI previews. The problem is these previews are always reloading and it is unclear what causes this error.

Tried to call dumpSchema or dumpTables - they show that even tables are not stored between app launches too.

My code sample:

import SharingGRDB
import OSLog

private let logger = Logger(subsystem: "Reminders", category: "Database")

class DBManager {
    static let shared = DBManager()
    
    @Dependency(\.defaultDatabase) var database
    
    @FetchOne var account: DBAccount!
    @FetchAll var accounts: [DBAccount]
    
    private init() { }
    
    func start() {
        try! prepareDependencies {
            $0.defaultDatabase = try appDatabase()
            try $0.defaultDatabase.write { db in
                try db.create(table: DBAccount.tableName) { t in
                    t.column("id", .integer)
                        .primaryKey(onConflict: .fail, autoincrement: true)
                    t.column("passedWelcomeScreen", .boolean)
                }
            }
            
            try $0.defaultDatabase.write { db in
                if (try? DBAccount.all.fetchOne(db)) == nil {
                    try DBAccount.insert(DBAccount.Draft(passedWelcomeScreen: false))
                        .execute(db)
                }
            }
            try $0.defaultDatabase.dumpSchema()
            try $0.defaultDatabase.dumpTables([DBAccount.tableName])
        }
    }
    
    private func appDatabase() throws -> any DatabaseWriter {
        var configuration = Configuration()
        configuration.foreignKeysEnabled = true
#if DEBUG
        configuration.prepareDatabase { db in
            db.trace(options: .profile) {
                logger.debug("\($0.expandedDescription)")
            }
        }
#endif
        @Dependency(\.context) var context
        let database: any DatabaseWriter
        if context == .live {
            let path = URL.documentsDirectory.appending(component: "db.sqlite").path()
            logger.info("open \(path)")
            database = try DatabasePool(path: path, configuration: configuration)
        } else {
            database = try DatabaseQueue(configuration: configuration)
        }
        var migrator = DatabaseMigrator()
#if DEBUG
        migrator.eraseDatabaseOnSchemaChange = true
#endif
        migrator.registerMigration("Create account table") { db in
            try db.create(table: DBAccount.tableName) { t in
                t.column("id", .integer)
                    .primaryKey(onConflict: .fail, autoincrement: true)
                t.column("passedWelcomeScreen", .boolean)
            }
        }
        try migrator.migrate(database)
        return database
    }
}

DBAccount table is created twice because I don't know where to place it and the app behaves like this table doesn't exist (and allows to create it). Tried to add ifNotExists param - the result is the same.

Maybe could you please provide a simple workable example where data is stored between app launches?

[mbrandonw]

Hi @gerchicov-vg, please refer to the sample apps to see how to set up a database. Your DBManager class is not necessary.

For example, in Reminders, we define a function for provisioning a migrated database:

https://github.com/pointfreeco/sharing-grdb/blob/main/Examples/Reminders/Schema.swift#L89

And then in the entry point of the app we prepare the defaultDatabase dependency:

https://github.com/pointfreeco/sharing-grdb/blob/bf54eb0fc5ee0cc2963d05977580fd70983ca903/Examples/Reminders/RemindersApp.swift#L8

Once that is done @FetchAll can be used anywhere in the app. We also have an article dedicated to this.

[gerchicov-vg]

Thanks, the problem in my code is this extra line:
@Dependency(\.defaultDatabase) var database

and appDatabase() contains its own variable database

I want to use this class to separate outer code from database dependencies.