Add static fetch helpers, find helpers (#296)

* Add static `fetch` helpers, `find`

Let's support more ergonomics with functions that complement GRDB's
functions.

This includes static versions of `fetchAll`, etc.:

```diff
-try Reminder.all.fetchAll(db)
+try Reminder.fetchAll(db)
```

As well as new APIs for finding and unwrapping primary keyed records:

```diff
-try Reminder.find(1).fetchOne(db)  // Optional<Reminder>
+try Reminder.find(db, key: 1)      // Reminder
```

This includes a method version, as well:

```swift
try Reminder.where(\.isCompleted).find(db, key: 1)
```

* wip

* remove fetchAll-keys (not pulling its weight)

* wip

Author: stephencelis

Examples/CaseStudies/DynamicQuery.swift

@@ -93,7 +93,7 @@ struct DynamicQueryDemo: SwiftUICaseStudy {
       return try Value(
         facts: search.fetchAll(db),
         searchCount: search.fetchCount(db),
-        totalCount: Fact.all.fetchCount(db)
+        totalCount: Fact.fetchCount(db)
       )
     }
   }

Examples/CaseStudies/TransactionDemo.swift

@@ -64,7 +64,7 @@ struct TransactionDemo: SwiftUICaseStudy {
     func fetch(_ db: Database) throws -> Value {
       try Value(
         facts: Fact.order { $0.id.desc() }.fetchAll(db),
-        count: Fact.all.fetchCount(db)
+        count: Fact.fetchCount(db)
       )
     }
   }

Examples/Examples.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved

@@ -208,7 +208,7 @@ struct ReminderFormPreview: PreviewProvider {
     let (remindersList, reminder) = try! prepareDependencies {
       $0.defaultDatabase = try Reminders.appDatabase()
       return try $0.defaultDatabase.write { db in
-        let remindersList = try RemindersList.all.fetchOne(db)!
+        let remindersList = try RemindersList.fetchOne(db)!
         return (
           remindersList,
           try Reminder.where { $0.remindersListID.eq(remindersList.id) }.fetchOne(db)!

Examples/Reminders/ReminderForm.swift

@@ -162,8 +162,8 @@ struct ReminderRowPreview: PreviewProvider {
     let _ = try! prepareDependencies {
       $0.defaultDatabase = try Reminders.appDatabase()
       try $0.defaultDatabase.read { db in
-        reminder = try Reminder.all.fetchOne(db)
-        remindersList = try RemindersList.all.fetchOne(db)!
+        reminder = try Reminder.fetchOne(db)
+        remindersList = try RemindersList.fetchOne(db)!
       }
     }
 

Examples/Reminders/ReminderRow.swift

@@ -367,8 +367,8 @@ struct RemindersDetailPreview: PreviewProvider {
       $0.defaultDatabase = try Reminders.appDatabase()
       return try $0.defaultDatabase.read { db in
         (
-          try RemindersList.all.fetchOne(db)!,
-          try Tag.all.fetchOne(db)!
+          try RemindersList.fetchOne(db)!,
+          try Tag.fetchOne(db)!
         )
       }
     }

Examples/Reminders/RemindersDetail.swift

@@ -12,7 +12,7 @@ extension BaseTestSuite {
     @Dependency(\.defaultDatabase) var database
 
     @Test func basics() async throws {
-      let remindersList = try await database.read { try RemindersList.all.fetchOne($0)! }
+      let remindersList = try await database.read { try RemindersList.fetchOne($0)! }
       let model = RemindersDetailModel(detailType: .remindersList(remindersList))
       try await model.$reminderRows.load()
       assertInlineSnapshot(of: model.reminderRows, as: .customDump) {
@@ -118,7 +118,7 @@ extension BaseTestSuite {
     }
 
     @Test func ordering() async throws {
-      let remindersList = try await database.read { try RemindersList.all.fetchOne($0)! }
+      let remindersList = try await database.read { try RemindersList.fetchOne($0)! }
       let model = RemindersDetailModel(detailType: .remindersList(remindersList))
 
       try await model.$reminderRows.load()
@@ -164,7 +164,7 @@ extension BaseTestSuite {
     }
 
     @Test func showCompleted() async throws {
-      let remindersList = try await database.read { try RemindersList.all.fetchOne($0)! }
+      let remindersList = try await database.read { try RemindersList.fetchOne($0)! }
       let model = RemindersDetailModel(detailType: .remindersList(remindersList))
 
       try await model.$reminderRows.load()
@@ -211,7 +211,7 @@ extension BaseTestSuite {
     }
 
     @Test func move() async throws {
-      let remindersList = try await database.read { try RemindersList.all.fetchOne($0)! }
+      let remindersList = try await database.read { try RemindersList.fetchOne($0)! }
       let model = RemindersDetailModel(detailType: .remindersList(remindersList))
 
       try await model.$reminderRows.load()
@@ -319,7 +319,7 @@ extension BaseTestSuite {
     }
 
     @Test func tagged() async throws {
-      let tag = try await database.read { try Tag.find("someday").fetchOne($0)! }
+      let tag = try await database.read { try Tag.find($0, key: "someday") }
       let model = RemindersDetailModel(detailType: .tags([tag]))
       try await model.$reminderRows.load()
       assertInlineSnapshot(of: model.reminderRows.map(\.reminder.title), as: .customDump) {

Examples/RemindersTests/RemindersDetailsTests.swift

@@ -39,7 +39,7 @@ struct SyncUpFormTests {
 
   @Test func updateExisting() async throws {
     let existingSyncUp = try await database.read { db in
-      try #require(try SyncUp.all.fetchOne(db))
+      try #require(try SyncUp.fetchOne(db))
     }
     let draft = SyncUp.Draft(existingSyncUp)
     let model = SyncUpFormModel(syncUp: draft)

Examples/SyncUpTests/SyncUpFormTests.swift

@@ -300,6 +300,8 @@ with SQLite to take full advantage of GRDB and SQLiteData.
 
 - ``StructuredQueriesCore/Statement``
 - ``StructuredQueriesCore/SelectStatement``
+- ``StructuredQueriesCore/Table``
+- ``StructuredQueriesCore/PrimaryKeyedTable``
 - ``QueryCursor``
 
 ### Observing model data

Sources/SQLiteData/Documentation.docc/SQLiteData.md

@@ -186,6 +186,25 @@ extension SelectStatement where QueryValue == (), Joins == () {
   }
 }
 
+extension SelectStatement where QueryValue == (), From: PrimaryKeyedTable, Joins == () {
+  /// Returns a single value fetched from the database for a given primary key.
+  ///
+  /// - Parameters
+  ///   - db: A database connection.
+  ///   - primaryKey: A primary key identifying a table row.
+  /// - Returns: A single value decoded from the database.
+  @inlinable
+  public func find(
+    _ db: Database,
+    key primaryKey: some QueryExpression<From.PrimaryKey>
+  ) throws -> From.QueryOutput {
+    guard let record = try asSelect().find(primaryKey).fetchOne(db) else {
+      throw NotFound()
+    }
+    return record
+  }
+}
+
 @available(iOS 17, macOS 14, tvOS 17, watchOS 10, *)
 extension SelectStatement where QueryValue == () {
   /// Returns an array of all values fetched from the database.