add

iOS-SwiftUI-Code/GRDB.swift-6.29.3/Documentation/Playgrounds/TransactionObserver.playground/Contents.swift

@@ -1,84 +0,0 @@
-//: To run this playground:
-//:
-//: - Open GRDB.xcworkspace
-//: - Select the GRDB scheme: menu Product > Scheme > GRDB
-//: - Build: menu Product > Build
-//: - Select the playground in the Playgrounds Group
-//: - Run the playground
-
-import GRDB
-
-
-// Create the database
-
-let dbQueue = try DatabaseQueue()   // Memory database
-var migrator = DatabaseMigrator()
-migrator.registerMigration("createPerson") { db in
-    try db.create(table: "person") { t in
-        t.autoIncrementedPrimaryKey("id")
-        t.column("name", .text).notNull()
-    }
-}
-migrator.registerMigration("createPet") { db in
-    try db.create(table: "pet") { t in
-        t.autoIncrementedPrimaryKey("id")
-        t.column("name", .text).notNull()
-        t.belongsTo("owner", inTable: "person", onDelete: .cascade)
-    }
-}
-try! migrator.migrate(dbQueue)
-
-
-//
-
-class TableChangeObserver : NSObject, TransactionObserver {
-    private var changedTableNames: Set<String> = []
-    
-    func observes(eventsOfKind eventKind: DatabaseEventKind) -> Bool { true }
-    
-    func databaseDidChange(with event: DatabaseEvent) {
-        changedTableNames.insert(event.tableName)
-    }
-    
-    func databaseDidCommit(_ db: Database) {
-        print("Changed table(s): \(changedTableNames.joined(separator: ", "))")
-        changedTableNames = []
-    }
-    
-    func databaseDidRollback(_ db: Database) {
-        changedTableNames = []
-    }
-}
-
-let observer = TableChangeObserver()
-dbQueue.add(transactionObserver: observer)
-
-
-//
-
-print("-- Changes without transaction")
-try dbQueue.inDatabase { db in
-    try db.execute(sql: "INSERT INTO person (name) VALUES (?)", arguments: ["Arthur"])
-    let arthurId = db.lastInsertedRowID
-    try db.execute(sql: "INSERT INTO person (name) VALUES (?)", arguments: ["Barbara"])
-    try db.execute(sql: "INSERT INTO pet (ownerId, name) VALUES (?, ?)", arguments: [arthurId, "Barbara"])
-    try db.execute(sql: "DELETE FROM person WHERE id = ?", arguments: [arthurId])
-}
-
-print("-- Rollbacked changes")
-try dbQueue.inTransaction { db in
-    try db.execute(sql: "INSERT INTO person (name) VALUES ('Arthur')")
-    try db.execute(sql: "INSERT INTO person (name) VALUES ('Barbara')")
-    return .rollback
-}
-
-
-print("-- Changes wrapped in a transaction")
-try dbQueue.write { db in
-    try db.execute(sql: "DELETE FROM person")
-    try db.execute(sql: "INSERT INTO person (name) VALUES (?)", arguments: ["Arthur"])
-    let arthurId = db.lastInsertedRowID
-    try db.execute(sql: "INSERT INTO person (name) VALUES (?)", arguments: ["Barbara"])
-    try db.execute(sql: "INSERT INTO pet (ownerId, name) VALUES (?, ?)", arguments: [arthurId, "Barbara"])
-    try db.execute(sql: "DELETE FROM person WHERE id = ?", arguments: [arthurId])
-}

iOS-SwiftUI-Code/GRDB.swift-6.29.3/Documentation/Playgrounds/TransactionObserver.playground/contents.xcplayground

@@ -1,4 +0,0 @@
-<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
-<playground version='5.0' target-platform='osx' display-mode='rendered' buildActiveScheme='true'>
-    <timeline fileName='timeline.xctimeline'/>
-</playground>