Realm Java
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This document discusses Realm, a mobile database solution that uses a column-based data structure for fast queries. It provides examples of how to query data using Realm by extending RealmObject classes, executing transactions, and using relationships, sorting, and asynchronous queries. The document also covers migrations, encryption, and an adapter for Realm.
Realm Java
- 1. Realm Java Leonardo YongUk Kim lk@realm.io
- 4. No more SQL
- 5. String query = "SELECT " + Owner.NAME + ", " + Dog.NAME + ", " + City.NAME + " FROM " + Owner.TABLE_NAME + " INNER JOIN " + Dog.TABLE_NAME + " ON " + Owner.DOG_ID + " = " + Dog.ID + " INNER JOIN " + City.TABLE_NAME + " ON " + Owner.CITY_ID + " = " + City.ID + " WHERE " + Owner.NAME = "'" + escape(queryName) + "'";
- 6. Use cases
- 9. Fastest
- 14. Why is it so fast?
- 21. Traditional data structure Column-based data structure • Padding bits are not needed anymore. • Queries for columns help the cache hit rate. • Boolean type fields are put into integers field. • Other fields are packaged as 1, 2, 4, 8, 16, 32, 64bits. • More space efficient than SQLite (~50%)
- 22. How to use?
- 24. Create a standalone object, and then copy it to Realm
- 25. Instantiate through the Realm directly
- 29. Sorting
- 30. Chaining
- 31. Aggregation
- 32. Iteration
- 33. Deletion
- 34. Async queries
- 38. Link queries RealmResults<Contact> contacts = realm.where(Contact.class).equalTo("emails.active", true).findAll();
- 39. Migrations
- 41. Encryption
- 42. Adapter
- 43. Q&A kr@realm.io