Room Database 之设置Entity

1、设置表名

在类名上面添加Entity注解，并为tableName赋值

@Entity(tableName = "fav_dishes_table")
class FavDish {
}

2、保存数据的条目

@ColumnInfo + val + 变量名 + ： + 保存类型

如保存的名称是image，数据类型是String

@ColumnInfo val image : String

设置主key为id自增长

@PrimaryKey(autoGenerate = true) val id : Int = 0

3、favarite_dish为表里的列的名字，favoriteDish为entity的属性名

 @ColumnInfo (name = "favorite_dish") val favoriteDish : Boolean,

4、创建Entity的两种方法

一种是data形式：

@Entity(tableName = "fav_dishes_table")
data class FavDish (
    @ColumnInfo val image : String ,
    @ColumnInfo val imageSource : String,
    @ColumnInfo val title : String,
    @ColumnInfo val type : String,
    @ColumnInfo val category : String,
    @ColumnInfo val ingredients : String,
    @ColumnInfo (name = "cooking_time") val cookingTime : String,
    @ColumnInfo (name = "instructions") val directionToCook : String,
    @ColumnInfo (name = "favorite_dish") val favoriteDish : Boolean,
    @PrimaryKey(autoGenerate = true) val id : Int = 0


)

另一种是class形式：

@Entity(tableName = "fav_dishes_table")
class FavDish (
    @PrimaryKey(autoGenerate = true)
    val id : Int = 0,
    @ColumnInfo val image : String,
    @ColumnInfo var imageSource : String,
    @ColumnInfo var title : String,
    @ColumnInfo var type : String,
    @ColumnInfo var category : String,
    @ColumnInfo var ingredients : String,
    @ColumnInfo (name = "cooking_time") var cookingTime : String,
    @ColumnInfo (name = "instructions") var directionToCook : String,
    @ColumnInfo (name = "favorite_dish") var favoriteDish : String,
)

注：

官方文档：

Android Room with a View - Kotlin  |  Android Developers