Android room database quick start

What is? Android Room database ？ 

        Android Room yes Google Published a and SQLite Related databases , It's a lightweight ORM（Object Relational Mapping） Object relational mapping database , It's essentially right Android Native SQLite Encapsulation , It's just relatively simpler than the native operation 、 Efficient , At present, there are similar databases on the market GreenDao、LitePal、Realm、ObjectBox wait .

Why use Android Room database ？

because Android Room Database has the following advantages over other databases ：

        1、SQL Queries are validated at compile time （ Each... Is checked at compile time @Query and @Entity Whether the grammar is wrong , Whether the corresponding table exists, etc ）, You don't have to wait until after running to query for errors , This can improve work efficiency .

        2、 Less code

        3、 And LiveData Integrate

How do you use it? Android Room database ？

Running environment ：

AndroidStudio 4.2.2

Specific use steps ：

1、 First in the project /app/build.gradle In the document dependencies Add the following dependencies to the object ： 

    implementation "androidx.room:room-runtime:2.3.0"
    annotationProcessor "androidx.room:room-compiler:2.3.0"