What is Android Room?

Android Room is a persistence library that provides an abstraction layer over SQLite. It consists of three major components: Database, Entity (representing tables), and DAO (Data Access Object for queries). Room provides compile-time SQL query verification and convenient annotations for database operations.

How are SQL types mapped to Kotlin types?

SQL types are mapped to Kotlin types suitable for Room. INTEGER maps to Int, BIGINT maps to Long, VARCHAR/TEXT map to String, BOOLEAN maps to Boolean, TIMESTAMP maps to Long (or Date), DATE maps to Long, REAL/FLOAT maps to Float, DOUBLE maps to Double, BLOB maps to ByteArray, and nullable columns use Type? (nullable Kotlin types).

What annotations are generated?

The tool generates @Entity(tableName = "...") for the class, @PrimaryKey for primary key columns, @ColumnInfo(name = "...") for each field, and @ForeignKey annotations for referenced tables. Optional @Dao interface with @Query, @Insert, @Update, @Delete methods can also be generated.

How are foreign keys handled?

Foreign key references in SQL are converted to Room @ForeignKey annotations in the @Entity declaration. The tool also generates foreignKeys parameter in the @Entity annotation with parent table, parent columns, and child columns properly mapped.

Is my SQL data sent to a server?

No, all processing happens entirely in your browser. Your SQL schema never leaves your device. The conversion is performed client-side using a regex-based parser.

SQL to Android Room Entity Generator Online

Include @Entity annotationInclude @Dao interfaceInclude TypeConverters

SQL Input (CREATE TABLE)

Room Entity Output

What is SQL to Android Room Entity Generator?

Android Room is the official persistence library recommended by Google for local data storage on Android devices. It sits on top of SQLite and provides compile-time verification of SQL queries, convenient annotation-based mapping between database rows and Kotlin data classes, and first-class support for reactive data observation via LiveData and Kotlin Flow. This converter takes your existing SQL CREATE TABLE definitions and produces ready-to-use Room Entity classes in Kotlin, complete with @Entity annotations, @PrimaryKey markers, @ColumnInfo overrides for snake_case-to-camelCase mapping, and @ForeignKey declarations for referential integrity. Optionally, it also generates @Dao interfaces containing standard CRUD method signatures and TypeConverters for storing complex types like Date as primitives that SQLite understands.

How to Use

Paste one or more CREATE TABLE statements into the SQL input area on the left
Pick the original database dialect — PostgreSQL, MySQL, or SQLite — so the parser interprets types correctly
Toggle the checkboxes to include @Entity annotations, @Dao interfaces, and TypeConverters as needed
Press the Generate Room Entities button and review the Kotlin output on the right
Copy the generated code into your Android project under the appropriate package directory

Why Use This Tool?

Produces idiomatic Kotlin data classes with proper nullable Type? syntax for columns that allow NULL

Automatically translates SQL column naming conventions (snake_case) to Kotlin field naming (camelCase) with @ColumnInfo annotations

Detects REFERENCES clauses and emits @ForeignKey annotations with entity, parentColumns, and childColumns fully populated

Optional @Dao interfaces give you typed CRUD methods — getAll, getById, insert, update, delete — without writing boilerplate

TypeConverters for Date-to-Long conversion are generated on demand so you can store timestamps without manual serialization

Tips & Best Practices

Room requires every entity to declare at least one @PrimaryKey. SERIAL and AUTO_INCREMENT columns are automatically marked as primary keys with autoGenerate = true
When using TypeConverters, remember to annotate your AppDatabase class with @TypeConverters(Converters::class) so Room knows how to handle Date fields
For columns that store complex objects, consider adding a custom TypeConverter rather than falling back to String serialization
Add the Room KSP processor to your build.gradle.kts: ksp("androidx.room:room-compiler:2.6.1") alongside the runtime dependency

Frequently Asked Questions

How does the converter map SQL types to Kotlin types for Room?

INTEGER and SERIAL become Int, BIGINT and BIGSERIAL become Long, SMALLINT becomes Int, VARCHAR and TEXT become String, BOOLEAN becomes Boolean, REAL and FLOAT become Float, DOUBLE and NUMERIC become Double, TIMESTAMP and DATETIME become Long (or Date if TypeConverters are enabled), UUID becomes String, and BLOB becomes ByteArray. Columns without NOT NULL receive the nullable ? suffix.

When should I avoid using Room and stick with raw SQLite?

If your app requires dynamic SQL constructed at runtime, complex analytical queries with window functions, or direct control over connection pooling and WAL checkpointing, Room's abstraction may add unnecessary overhead. Room also does not support full-text search configuration or custom SQLite extensions natively.

What does the @Dao interface include?

The generated @Dao interface contains five methods: getAll() returning a List of the entity, getById() returning a single nullable entity, insert() using @Insert with vararg parameters, update() using @Update, and delete() using @Delete. You can extend this interface with custom @Query methods for your specific use case.

How are foreign keys represented in the generated entities?

SQL REFERENCES clauses are converted to @ForeignKey annotations inside the @Entity declaration. Each foreign key specifies the parent entity class, the parent column, the child column, and the onDelete action (defaults to NO_ACTION). Room validates these constraints at compile time.

Is my SQL schema uploaded to any server during conversion?

No. The entire parsing and code generation process runs inside your browser using a client-side regex parser. Your database schema never leaves your device, and no network requests are made.

Can I use the generated entities with Kotlin Multiplatform?

The generated code targets the Android Room library specifically. For Kotlin Multiplatform projects, consider using SQLDelight instead, which has its own code generation pipeline and supports iOS, JVM, and JS targets alongside Android.

Real-world Examples

Migrating a SQLite-backed note-taking app to Room

A note-taking app stores notes and categories in SQLite. The developer pastes the existing schema to generate Room entities and DAOs, then replaces raw SQLiteDatabase calls with typed DAO method invocations.

Offline-first chat application with message threading

A messaging app uses Room for local caching of conversations and messages. Foreign keys enforce the relationship between conversations and their messages, ensuring referential integrity on the device.

SQL to Android Room Entity Generator