android - 如何在房间数据库中实现sqlite查询？

Question

这是我想在房间数据库中使用的 SQLite 查询这是第一个尝试插入数据，如果数据已经存在则使用 id 更新数据

INSERT INTO books(id, title, author, year_published)  VALUES(@id, @title, @author, @year_published)
 ON DUPLICATE KEY UPDATE title = @title,  author = @author;

Answer 1

Room 支持@RawQuery 注释来在运行时构造查询。所以你需要:

@Dao
interface BooksDao{
    @RawQuery
    List<Book> books(SupportSQLiteQuery query);
}

并以旧式风格创建您的查询:

String queryString = "here is your query";
List<Object> args = new ArrayList(); // here is your args for your query

然后执行您的查询:

SimpleSQLiteQuery query = new SimpleSQLiteQuery(queryString, args.toArray());
List<Book> result = booksDao.books(query);