How to annotate a default value inside a android room entity?

Question

I couldn't find any information how to annotate a SQL - "DEFAULT" value while looking into the @ColumnInfo docs for the new Android Persistence Library.

Does Room even provide an annotation for default values?

My current solution would be to manually create the corresponding Table ...

CREATE TABLE MyTable (   ...   MyDefaultValuedCol  TEXT DEFAULT 'Default Value',   MyDefaultFlagCol    INT  DEFAULT 1 ) 

... and put Room on top.

@Entity(tableName = "MyTable") class MyClass {     ...      public String MyDefaultValuedCol;      public boolean MyDefaultFlagCol;  } 

Answer 1

With the release of room persistence 2.2.0, there's a new property added to @ColumnInfo annotation which can be used to specify the default value of a column. See documentation.

@Entity(tableName = "users") data class User(     @PrimaryKey val id: Long,     @ColumnInfo(name = "user_name", defaultValue = "temp") val name: String     @ColumnInfo(name = "last_modified", defaultValue = "CURRENT_TIMESTAMP" ) val lastModified: String ) 

Answer 2

Room hasn't any annotation for default value, but you can set default value in your entity like this:

@Entity(tableName = "MyTable") class MyClass {     ...      public String MyDefaultValuedCol = "defaultString";      public boolean MyDefaultFlagCol = true;  }