@SuppressWarnings(RoomWarnings.CURSOR_MISMATCH) @Query("SELECT * FROM post_entity") suspend fun getAll(): List<PostEntity> 编译报错 Not sure how to convert a Cursor to this method's return type (java.lang.Object). public abstract java.lang.Object getAll(@org.jetbrains.annotations.NotNull ^

这是一个 Kotlin 语言中的函数，它使用了 Room Persistence Library，用于从数据库中查询所有的 PostEntity 并以 List<PostEntity> 的形式返回。编译错误可能是由于返回类型不匹配所导致的。建议检查代码中的 Room 数据库相关的注解和配置是否正确，以及是否有定义正确的数据实体类。

相关问题

@Dao interface PostDao { @Insert(onConflict = OnConflictStrategy.REPLACE) suspend fun insertPost(post: PostEntity) @Query("SELECT * FROM post_entity") suspend fun getAll(): List<PostEntity> } 编译报错 The query returns some columns [path, content, time, likeCount, id] which are not used by java.lang.Object. You can use @ColumnInfo annotation on the fields to specify the mapping. You can annotate the method with @RewriteQueriesToDropUnusedColumns to direct Room to rewrite your query to avoid fetching unused columns. You can suppress this warning by annotating the method with @SuppressWarnings(RoomWarnings.CURSOR_MISMATCH). Columns returned by the query: path, content, time, likeCount, id. Fields in java.lang.Object: . public abstract java.lang.Object getAll(@org.jetbrains.annotations.NotNull ^

对于这个问题，可能是由于你的查询返回了一些列，但在 Java.lang.Object 中没有使用。你可以使用 @ColumnInfo 注释在字段上指定映射，并使用 @RewriteQueriesToDropUnusedColumns 注释方法来重写查询以避免获取未使用的列。你还可以使用 @SuppressWarnings(RoomWarnings.CURSOR_MISMATCH) 注释来抑制此警告。查询返回的列是：path、content、time、likeCount 和 id。请检查一下你的代码并按照提示进行修改。

@Entity(tableName = "post_entity") data class PostEntity( var path :String, var content:String, var time:Long, var likeCount:Int, @PrimaryKey(autoGenerate = true) var id: Int = 0 ) @Dao interface PostDao { @Insert(onConflict = OnConflictStrategy.REPLACE) suspend fun insertPost(post: PostEntity) @Query("SELECT * FROM post_entity") suspend fun getAll(): List<PostEntity> } 编译报错 The query returns some columns [path, content, time, likeCount, id] which are not used by java.lang.Object. You can use @ColumnInfo annotation on the fields to specify the mapping. You can annotate the method with @RewriteQueriesToDropUnusedColumns to direct Room to rewrite your query to avoid fetching unused columns. You can suppress this warning by annotating the method with @SuppressWarnings(RoomWarnings.CURSOR_MISMATCH). Columns returned by the query: path, content, time, likeCount, id. Fields in java.lang.Object: . public abstract java.lang.Object getAll(@org.jetbrains.annotations.NotNull ^ 帮我改正

这个错误是由于你的查询返回的字段与实体类中定义的字段不一致所导致的。为了解决这个错误，你需要在实体类中使用 @ColumnInfo 注解来显式指定每个字段的映射关系，指定与查询返回的字段相同的名称。另外，你可以在 DAO 接口的方法上添加 @SuppressWarnings(RoomWarnings.CURSOR_MISMATCH) 注解来抑制警告。此外，还可以使用 @RewriteQueriesToDropUnusedColumns 注解来让 Room 重写查询以避免获取未使用的列。以下是修改后的代码：

@Entity(tableName = "post_entity")
data class PostEntity(
@ColumnInfo(name = "path") var path: String,
@ColumnInfo(name = "content") var content: String,
@ColumnInfo(name = "time") var time: Long,
@ColumnInfo(name = "likeCount") var likeCount: Int,
@PrimaryKey(autoGenerate = true) @ColumnInfo(name = "id") var id: Int = 0
)

@Dao
interface PostDao {
@Insert(onConflict = OnConflictStrategy.REPLACE)
suspend fun insertPost(post: PostEntity)

@SuppressWarnings(RoomWarnings.CURSOR_MISMATCH)
@Query("SELECT * FROM post_entity")
suspend fun getAll(): List<PostEntity>
}