[英]How to get multiple counts from room database?
I want to return multiple counts from Room
Select query in android
.我想从 android 中的Room
android
查询返回多个计数。 My query is like我的查询就像
Select Count(CASE WHEN x = '0' or x = '2'), Count(Case when a = '33' or a = '23') FROM my_table WHERE id=10
I want above query to return something as list which will contain values of both the above Count()
function.我希望上面的查询以列表的形式返回一些内容,其中将包含上述Count()
function 的值。 This can be easily done using SQLite
but I want to use it in room
.这可以使用SQLite
轻松完成,但我想在room
中使用它。
You can give names to the counts and return them as a class, like:您可以为计数命名并将它们作为 class 返回,例如:
data class MyCounts(
@ColumnInfo(name = "first_count")
val firstCount: Int,
@ColumnInfo(name = "second_count")
val secondCount: Int
)
@Dao
interface MyDao {
@Query("SELECT COUNT(*) as first_count, COUNT(*) as second_count from my_table")
suspend fun getMyCounts(): MyCounts
}
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