sqlite: enable foreign key constraints by default

doc/api/sqlite.md

@@ -107,6 +107,11 @@ added: v22.5.0
   * `open` {boolean} If `true`, the database is opened by the constructor. When
     this value is `false`, the database must be opened via the `open()` method.
     **Default:** `true`.
+  * `enableForeignKeyConstraints` {boolean} If `true`, foreign key constraints
+    are enabled. This is recommended but can be disabled for compatibility with
+    legacy database schemas. The enforcement of foreign key constraints can be
+    enabled and disabled after opening the database using
+    [`PRAGMA foreign_keys`][]. **Default:** `true`.
 
 Constructs a new `DatabaseSync` instance.
 
@@ -317,6 +322,7 @@ exception.
 
 [SQL injection]: https://en.wikipedia.org/wiki/SQL_injection
 [`--experimental-sqlite`]: cli.md#--experimental-sqlite
+[`PRAGMA foreign_keys`]: https://www.sqlite.org/pragma.html#pragma_foreign_keys
 [`sqlite3_changes64()`]: https://www.sqlite.org/c3ref/changes.html
 [`sqlite3_close_v2()`]: https://www.sqlite.org/c3ref/close.html
 [`sqlite3_exec()`]: https://www.sqlite.org/c3ref/exec.html

src/node_sqlite.cc

@@ -82,12 +82,14 @@ inline void THROW_ERR_SQLITE_ERROR(Isolate* isolate, sqlite3* db) {
 DatabaseSync::DatabaseSync(Environment* env,
                            Local<Object> object,
                            Local<String> location,
-                           bool open)
+                           bool open,
+                           bool enable_foreign_keys_on_open)
     : BaseObject(env, object) {
   MakeWeak();
   node::Utf8Value utf8_location(env->isolate(), location);
   location_ = utf8_location.ToString();
   connection_ = nullptr;
+  enable_foreign_keys_on_open_ = enable_foreign_keys_on_open;
 
   if (open) {
     Open();
@@ -116,6 +118,15 @@ bool DatabaseSync::Open() {
   int flags = SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE;
   int r = sqlite3_open_v2(location_.c_str(), &connection_, flags, nullptr);
   CHECK_ERROR_OR_THROW(env()->isolate(), connection_, r, SQLITE_OK, false);
+
+  int foreign_keys_enabled;
+  r = sqlite3_db_config(connection_,
+                        SQLITE_DBCONFIG_ENABLE_FKEY,
+                        static_cast<int>(enable_foreign_keys_on_open_),
+                        &foreign_keys_enabled);
+  CHECK_ERROR_OR_THROW(env()->isolate(), connection_, r, SQLITE_OK, false);
+  CHECK_EQ(foreign_keys_enabled, enable_foreign_keys_on_open_);
+
   return true;
 }
 
@@ -157,6 +168,7 @@ void DatabaseSync::New(const FunctionCallbackInfo<Value>& args) {
   }
 
   bool open = true;
+  bool enable_foreign_keys = true;
 
   if (args.Length() > 1) {
     if (!args[1]->IsObject()) {
@@ -179,9 +191,28 @@ void DatabaseSync::New(const FunctionCallbackInfo<Value>& args) {
       }
       open = open_v.As<Boolean>()->Value();
     }
+
+    Local<String> enable_foreign_keys_string =
+        FIXED_ONE_BYTE_STRING(env->isolate(), "enableForeignKeyConstraints");
+    Local<Value> enable_foreign_keys_v;
+    if (!options->Get(env->context(), enable_foreign_keys_string)
+             .ToLocal(&enable_foreign_keys_v)) {
+      return;
+    }
+    if (!enable_foreign_keys_v->IsUndefined()) {
+      if (!enable_foreign_keys_v->IsBoolean()) {
+        node::THROW_ERR_INVALID_ARG_TYPE(
+            env->isolate(),
+            "The \"options.enableForeignKeyConstraints\" argument must be a "
+            "boolean.");
+        return;
+      }
+      enable_foreign_keys = enable_foreign_keys_v.As<Boolean>()->Value();
+    }
   }
 
-  new DatabaseSync(env, args.This(), args[0].As<String>(), open);
+  new DatabaseSync(
+      env, args.This(), args[0].As<String>(), open, enable_foreign_keys);
 }
 
 void DatabaseSync::Open(const FunctionCallbackInfo<Value>& args) {

src/node_sqlite.h

@@ -21,7 +21,8 @@ class DatabaseSync : public BaseObject {
   DatabaseSync(Environment* env,
                v8::Local<v8::Object> object,
                v8::Local<v8::String> location,
-               bool open);
+               bool open,
+               bool enable_foreign_keys_on_open);
   void MemoryInfo(MemoryTracker* tracker) const override;
   static void New(const v8::FunctionCallbackInfo<v8::Value>& args);
   static void Open(const v8::FunctionCallbackInfo<v8::Value>& args);
@@ -43,6 +44,7 @@ class DatabaseSync : public BaseObject {
   std::string location_;
   sqlite3* connection_;
   std::unordered_set<StatementSync*> statements_;
+  bool enable_foreign_keys_on_open_;
 };
 
 class StatementSync : public BaseObject {

test/parallel/test-sqlite-database-sync.js

@@ -50,6 +50,42 @@ suite('DatabaseSync() constructor', () => {
       message: /The "options\.open" argument must be a boolean/,
     });
   });
+
+  test('throws if options.enableForeignKeyConstraints is provided but is not a boolean', (t) => {
+    t.assert.throws(() => {
+      new DatabaseSync('foo', { enableForeignKeyConstraints: 5 });
+    }, {
+      code: 'ERR_INVALID_ARG_TYPE',
+      message: /The "options\.enableForeignKeyConstraints" argument must be a boolean/,
+    });
+  });
+
+  test('enables foreign key constraints by default', (t) => {
+    const dbPath = nextDb();
+    const db = new DatabaseSync(dbPath);
+    db.exec(`
+      CREATE TABLE foo (id INTEGER PRIMARY KEY);
+      CREATE TABLE bar (foo_id INTEGER REFERENCES foo(id));
+    `);
+    t.after(() => { db.close(); });
+    t.assert.throws(() => {
+      db.exec('INSERT INTO bar (foo_id) VALUES (1)');
+    }, {
+      code: 'ERR_SQLITE_ERROR',
+      message: 'FOREIGN KEY constraint failed',
+    });
+  });
+
+  test('allows disabling foreign key constraints', (t) => {
+    const dbPath = nextDb();
+    const db = new DatabaseSync(dbPath, { enableForeignKeyConstraints: false });
+    db.exec(`
+      CREATE TABLE foo (id INTEGER PRIMARY KEY);
+      CREATE TABLE bar (foo_id INTEGER REFERENCES foo(id));
+    `);
+    t.after(() => { db.close(); });
+    db.exec('INSERT INTO bar (foo_id) VALUES (1)');
+  });
 });
 
 suite('DatabaseSync.prototype.open()', () => {