INSERT statements should not return an optional

Author: wickwirew

Sources/Compiler/Gen/Language.swift

@@ -264,7 +264,8 @@ extension Language {
         // Will return an array if it returns many or optional if its a single result
         let singleOrMany: (GenerationType) -> GenerationType = {
             switch statement.outputCardinality {
-            case .single: .optional($0)
+            // INSERTs will always return a value so no need to do optional
+            case .single: statement.isInsert ? $0 : .optional($0)
             case .many: .array($0)
             }
         }

Sources/Compiler/Sema/Statement.swift

@@ -37,6 +37,13 @@ public struct Statement {
         return definition?.name
     }
 
+    /// Whether or not the source syntax is an INSERT statement
+    public var isInsert: Bool {
+        if syntax is InsertStmtSyntax { return true }
+        guard let definition = syntax as? QueryDefinitionStmtSyntax else { return false }
+        return definition.statement is InsertStmtSyntax
+    }
+    
     /// Replaces the definition with the given input
     public func with(definition: Definition?) -> Statement {
         return Statement(

Tests/CompilerTests/Gen/Queries.sql

@@ -1,5 +1,5 @@
 insertUser:
-INSERT INTO user VALUES (?, ?, ?, ?, ?, ?, ?);
+INSERT INTO user VALUES (?, ?, ?, ?, ?, ?, ?) RETURNING id;
 
 selectUsers:
 SELECT * FROM user;

Tests/CompilerTests/Gen/Swift.output

@@ -203,7 +203,7 @@ protocol QueriesQueries: ConnectionWrapper {
 
 struct QueriesQueriesNoop: QueriesQueries {
     let connection: any Connection = NoopConnection()
-    let insertUser: AnyQuery<InsertUserInput, ()>
+    let insertUser: AnyQuery<InsertUserInput, Int>
     let selectUsers: AnyQuery<(), [User]>
     let selectUserById: AnyQuery<Int, User?>
     let selectUserByIds: AnyQuery<[Int], [User]>
@@ -236,15 +236,15 @@ struct QueriesQueriesNoop: QueriesQueries {
 struct QueriesQueriesImpl: QueriesQueries {
     let connection: any Connection
 
-    var insertUser: DatabaseQuery<InsertUserInput, ()> {
-        DatabaseQuery<InsertUserInput, ()>(
+    var insertUser: DatabaseQuery<InsertUserInput, Int> {
+        DatabaseQuery<InsertUserInput, Int>(
             .write,
             in: connection,
             watchingTables: ["user"]
         ) { input, tx in
             let statement = try Otter.Statement(
                 """
-                INSERT INTO user VALUES (?, ?, ?, ?, ?, ?, ?)
+                INSERT INTO user VALUES (?, ?, ?, ?, ?, ?, ?) RETURNING id
                 """,
                 transaction: tx
             )
@@ -255,7 +255,7 @@ struct QueriesQueriesImpl: QueriesQueries {
             try statement.bind(value: input.favoriteNumber, to: 5)
             try statement.bind(value: input.randomValue, to: 6)
             try statement.bind(value: input.bornOn, to: 7, using: CustomDateDatabaseValueAdapter.self, as: String.self)
-            _ = try statement.step()
+            return try statement.fetchOne()
         }
     }
 
@@ -410,13 +410,13 @@ struct DB: Database{
     }
 }
 
-typealias InsertUserQuery = Query<InsertUserInput, ()>
+typealias InsertUserQuery = Query<InsertUserInput, Int>
 extension Query where Input == InsertUserInput {
     func execute(id: Int, firstName: String, lastName: String, preference: Bool?, favoriteNumber: Int?, randomValue: SQLAny?, bornOn: Date?) async throws -> Output {
         try await execute(with: InsertUserInput(id: id, firstName: firstName, lastName: lastName, preference: preference, favoriteNumber: favoriteNumber, randomValue: randomValue, bornOn: bornOn))
     }
 
-    func execute(id: Int, firstName: String, lastName: String, preference: Bool?, favoriteNumber: Int?, randomValue: SQLAny?, bornOn: Date?, tx: borrowing Transaction) async throws -> Output {
+    func execute(id: Int, firstName: String, lastName: String, preference: Bool?, favoriteNumber: Int?, randomValue: SQLAny?, bornOn: Date?, tx: borrowing Transaction) throws -> Output {
         try execute(with: InsertUserInput(id: id, firstName: firstName, lastName: lastName, preference: preference, favoriteNumber: favoriteNumber, randomValue: randomValue, bornOn: bornOn), tx: tx)
     }
 
@@ -435,7 +435,7 @@ extension Query where Input == SelectUserWithManyInputsInput {
         try await execute(with: SelectUserWithManyInputsInput(id: id, firstName: firstName))
     }
 
-    func execute(id: Int, firstName: String, tx: borrowing Transaction) async throws -> Output {
+    func execute(id: Int, firstName: String, tx: borrowing Transaction) throws -> Output {
         try execute(with: SelectUserWithManyInputsInput(id: id, firstName: firstName), tx: tx)
     }