我想给用户一个选项，当他在父表中删除一个项目时，要么级联删除，要么给引用外键的子表中的项目设置null，这在sqlite中是可能的吗？或者我必须在我的代码中这样做？这些是我当前在创建两个表时使用的命令，当前在删除一个类别时，分配给这个类别的项被设置为null，基本上我想给用户一个选项来删除所有这些项，最好是在sql代码中。

await database.execute(
      "CREATE TABLE $TABLE_CATEGORIES ("
      "$COLUMN_CATEGORYID INTEGER PRIMARY KEY,"
      "$COLUMN_CATEGORYNAME TEXT"
      ")",
    );
    await database.execute(
      "CREATE TABLE $TABLE_GROCERIES ("
      "$COLUMN_ID INTEGER PRIMARY KEY,"
      "$COLUMN_NAME TEXT,"
      "$COLUMN_PPU REAL,"
      "$COLUMN_BASE REAL,"
      "$COLUMN_STOCK REAL,"
      "$COLUMN_CATEGORYID INTEGER,"
      "FOREIGN KEY($COLUMN_CATEGORYID) REFERENCES $TABLE_CATEGORIES($COLUMN_CATEGORYID) ON DELETE SET NULL"
      ")",
    );