How to make primary key as autoincrement for Room Persistence lib

Question

I am creating an Entity  Room Persistence Library  class Food  where I want to make foodId as autoincrement   Entity class Food var foodName  String  var foodDesc  String  var protein  Double  var carbs  Double  var fat  Double         PrimaryKey     var foodId  Int   0     var calories  Double   0 toDouble      How can I set foodId an autoincrement field

User · Answer

You can add  PrimaryKey autoGenerate   true  like this    Entity data class Food          var foodName  String           var foodDesc  String           var protein  Double           var carbs  Double           var fat  Double         PrimaryKey autoGenerate   true      var foodId  Int   0    or foodId  Int    null     var calories  Double   0 toDouble

User · Answer

You need to use the autoGenerate property  Your primary key annotation should be like this    PrimaryKey autoGenerate   true    Reference for PrimaryKey

User · Answer

Entity tableName    user   data class User    PrimaryKey autoGenerate   true   var id  Int          var name  String         var dob  String         var address  String         var gender  String         constructor   this null

User · Answer

add  PrimaryKey autoGenerate   true    Entity public class User         PrimaryKey autoGenerate   true      private int id        ColumnInfo name    full name       private String name        ColumnInfo name    phone       private String phone       public User                 type-1     public User String name  String phone            this name   name          this phone   phone               type-2     public User int id  String name  String phone            this id   id          this name   name          this phone   phone             while storing data      type-1  db userDao   InsertAll new User sName sPhone         type-2  db userDao   InsertAll new User 0 sName sPhone          type-1      If you are not passing value for primary key  by default it will 0 or   null    type-2  Put null or zero for the id while creating object  my case user object   If the field type is long or int  or its TypeConverter converts it to a long or int   Insert methods treat 0 as not-set while inserting the item   If the field s type is Integer or Long  Object   or its TypeConverter converts it to an Integer or a Long   Insert methods treat null as not-set while inserting the item

User · Answer

This works for me   Entity tableName    quot note table quot   data class Note       ColumnInfo name  quot title quot   var title  String       ColumnInfo name  quot description quot   var description  String    quot  quot        ColumnInfo name  quot priority quot   var priority  Int       PrimaryKey autoGenerate   true  var id  Int   0  last so that we don t have to pass an ID value or named arguments    Note that the id is last to avoid having to use named arguments when creating the entity  before inserting it into Room  Once it s been added to room  use the id when updating the entity

User · Answer

Its unbelievable after so many answers  but I did it little differently in the end  I don t like primary key to be nullable  I want to have it as first argument and also want to insert without defining it and also it should not be var   Entity tableName    quot employments quot   data class Employment       PrimaryKey autoGenerate   true  val id  Long       ColumnInfo name    quot code quot   val code  String       ColumnInfo name    quot title quot   val name  String        constructor code  String  name  String    this 0  code  name

User · Answer

For example  if you have a users entity you want to store  with fields  firstname  lastname   email  and you want autogenerated id  you do this    Entity tableName    users   data class Users      PrimaryKey autoGenerate   true     val id  Long     val firstname  String     val lastname  String     val email  String     Room will then autogenerate and auto-increment the id field

User · Answer

Annotate your Entity class with the code below  In Java   PrimaryKey autoGenerate   true  private int id   In Kotlin   PrimaryKey autoGenerate   true  var id  Int  Room will then auto-generate and auto-increment the id field

[android] How to make primary key as autoincrement for Room Persistence lib

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