[Aleksander Piotrowski] Is there a room for Room?

Presentation from GDG DevFest Ukraine 2017 - the biggest community-driven Google tech conference in the CEE.

Learn more at: https://devfest.gdg.org.ua

Transcript

1. Is there a room for Room? Aleksander Piotrowski @pelotasplus
2. Why Google created Room?
4. Dianne Hackborn
6. "How should I design my Android application? What kind of MVC pattern should I use? What should I use for an event bus?" https://plus.google.com/+DianneHackborn/posts/FXCCYxepsDU
7. "How should I design my Android application? What kind of MVC pattern should I use? What should I use for an event bus?" We often see questions from developers that are asking from the Android platform engineers about the kinds of design patterns and architectures they use in their apps. But the answer, maybe surprisingly, is we often don't have a strong opinion or really an opinion at all. https://plus.google.com/+DianneHackborn/posts/FXCCYxepsDU
9. Why Google created Room? • … because (now) they care • not only Room but Android Architecture Components
11. App Data model
28. Data model Invoice • Reference number • Seller/buyer data • Tax information • Total amount • … around 25 different properties • Invoice ID
29. Data model Invoice • Reference number • Seller/buyer data • Tax information • Total amount • … around 25 different properties • Invoice ID Advance payment • Amount • Date • Invoice ID • Advance payment ID
30. Data model Invoice • Reference number • Seller/buyer data • Tax information • Total amount • … around 25 different properties • Invoice ID Advance payment • Amount • Date • Invoice ID • Advance payment ID
31. Data model Invoice • Reference number • Seller/buyer data • Tax information • Total amount • … around 25 different properties • Invoice ID Advance payment • Amount • Date • Invoice ID • Advance payment ID
32. Dependencies
33. Room: build.gradle dependencies { [...] implementation 'io.reactivex.rxjava2:rxjava:2.1.0' implementation 'android.arch.persistence.room:runtime:1.0.0-alpha4' implementation 'android.arch.persistence.room:rxjava2:1.0.0-alpha4' annotationProcessor 'android.arch.persistence.room:compiler:1.0.0-alpha4' testImplementation 'android.arch.persistence.room:testing:1.0.0-alpha4' [...] }
34. Room: build.gradle dependencies { [...] implementation 'io.reactivex.rxjava2:rxjava:2.1.2' implementation 'android.arch.persistence.room:runtime:1.0.0-alpha9-1' implementation 'android.arch.persistence.room:rxjava2:1.0.0-alpha9-1' annotationProcessor 'android.arch.persistence.room:compiler:1.0.0-alpha9-1' testImplementation 'android.arch.persistence.room:testing:1.0.0-alpha9-1' [...] }
35. How to use Room? Three magic pieces
36. Database Model aka entity DAO
37. Entities aka data model
38. public class InvoiceData { }
39. public class InvoiceData { private long id; }
40. public class InvoiceData { private long id; private String invoiceNo; // "Invoice GDG/4/2017" }
41. public class InvoiceData { private long id; private String invoiceNo; private long amountGross; private long vatRate; // ... }
42. public class InvoiceData { public long id; public String invoiceNo; public long amountGross; public long vatRate; // ... }
43. @Entity(tableName = "Invoices") public class InvoiceData { public long id; public String invoiceNo; public long amountGross; public long vatRate; // ... }
44. @Entity(tableName = "Invoices") public class InvoiceData { @PrimaryKey @ColumnInfo(name = "id") public long id; public String invoiceNo; public long amountGross; public long vatRate; // ... }
45. @Entity(tableName = "Invoices") public class InvoiceData { @PrimaryKey @ColumnInfo(name = "id") public long id; @ColumnInfo(name = "invoice_no") public String invoiceNo; public long amountGross; public long vatRate; // ... }
46. @Entity(tableName = "Invoices") public class InvoiceData { @PrimaryKey @ColumnInfo(name = "id") public long id; @ColumnInfo(name = "invoice_no") public String invoiceNo; public long amountGross; public long vatRate; // … public long dontPersistThisOnePlease; }
47. @Entity(tableName = "Invoices") public class InvoiceData { @PrimaryKey @ColumnInfo(name = "id") public long id; @ColumnInfo(name = "invoice_no") public String invoiceNo; public long amountGross; public long vatRate; // … @Ignore public long dontPersistThisOnePlease; }
48. public class AdvancePaymentData { public long id; public long invoiceId; public long amount; public long date; } @Entity(tableName = "Invoices") public class InvoiceData { @PrimaryKey @ColumnInfo(name = "id") public long id; @ColumnInfo(name = "invoice_no") public String invoiceNo; public long amountGross; public long vatRate; // ... }
49. @Entity(tableName = "AdvancePayments") public class AdvancePaymentData { public long id; public long invoiceId; public long amount; public long date; } @Entity(tableName = "Invoices") public class InvoiceData { @PrimaryKey @ColumnInfo(name = "id") public long id; @ColumnInfo(name = "invoice_no") public String invoiceNo; public long amountGross; public long vatRate; // ... }
50. @Entity(tableName = "AdvancePayments") public class AdvancePaymentData { @PrimaryKey @ColumnInfo(name = "id") public long id; public long invoiceId; public long amount; public long date; } @Entity(tableName = "Invoices") public class InvoiceData { @PrimaryKey @ColumnInfo(name = "id") public long id; @ColumnInfo(name = "invoice_no") public String invoiceNo; public long amountGross; public long vatRate; // ... }
51. @Entity(tableName = "AdvancePayments") public class AdvancePaymentData { @PrimaryKey @ColumnInfo(name = "id") public long id; @ColumnInfo(name = "invoice_id") public long invoiceId; @ColumnInfo(name = "amount") public long amount; @ColumnInfo(name = "date") public long date; } @Entity(tableName = "Invoices") public class InvoiceData { @PrimaryKey @ColumnInfo(name = "id") public long id; @ColumnInfo(name = "invoice_no") public String invoiceNo; public long amountGross; public long vatRate; // ... }
52. @Entity(tableName = "Invoices") public class InvoiceData { @PrimaryKey @ColumnInfo(name = "id") public long id; @ColumnInfo(name = "invoice_no") public String invoiceNo; public long amountGross; public long vatRate; // ... } @Entity(tableName = "AdvancePayments") public class AdvancePaymentData { @PrimaryKey @ColumnInfo(name = "id") public long id; @ColumnInfo(name = "invoice_id") public long invoiceId; @ColumnInfo(name = "amount") public long amount; @ColumnInfo(name = "date") public long date; }
53. Relations between data models
54. @Entity(tableName = "Invoices") public class InvoiceData { @PrimaryKey @ColumnInfo(name = "id") public long id; @ColumnInfo(name = "invoice_no") public String invoiceNo; public long amountGross; public long vatRate; // ... } @Entity(tableName = "AdvancePayments") public class AdvancePaymentData { @PrimaryKey @ColumnInfo(name = "id") public long id; @ColumnInfo(name = "invoice_id") public long invoiceId; @ColumnInfo(name = "amount") public long amount; @ColumnInfo(name = "date") public long date; }
55. @Entity(tableName = "Invoices") public class InvoiceData { @PrimaryKey @ColumnInfo(name = "id") public long id; @ColumnInfo(name = "invoice_no") public String invoiceNo; public long amountGross; public long vatRate; // ... } @Entity(tableName = "AdvancePayments") public class AdvancePaymentData { @PrimaryKey @ColumnInfo(name = "id") public long id; @ColumnInfo(name = "invoice_id") public long invoiceId; @ColumnInfo(name = "amount") public long amount; @ColumnInfo(name = "date") public long date; }
56. @Entity(tableName = "Invoices") public class InvoiceData { @PrimaryKey @ColumnInfo(name = "id") public long id; @ColumnInfo(name = "invoice_no") public String invoiceNo; public long amountGross; public long vatRate; // ... } @Entity(tableName = "AdvancePayments") public class AdvancePaymentData { @PrimaryKey @ColumnInfo(name = "id") public long id; @ColumnInfo(name = "invoice_id") public long invoiceId; @ColumnInfo(name = "amount") public long amount; @ColumnInfo(name = "date") public long date; }
57. @Entity(tableName = "AdvancePayments") public class AdvancePaymentData { @PrimaryKey @ColumnInfo(name = "id") public long id; @ColumnInfo(name = "invoice_id") public long invoiceId; @ColumnInfo(name = "amount") public long amount; @ColumnInfo(name = "date") public long date; } @Entity(tableName = "Invoices") public class InvoiceData { @PrimaryKey @ColumnInfo(name = "id") public long id; @ColumnInfo(name = "invoice_no") public String invoiceNo; public long amountGross; public long vatRate; // ... } ?
58. @Entity(tableName = "Invoices") public class InvoiceData { @PrimaryKey @ColumnInfo(name = "id") public long id; @ColumnInfo(name = "invoice_no") public String invoiceNo; public long amountGross; public long vatRate; // … @OneToMany public List<AdvancePaymentData> advancePayments; } @Entity(tableName = "AdvancePayments") public class AdvancePaymentData { @PrimaryKey @ColumnInfo(name = "id") public long id; @ColumnInfo(name = "invoice_id") public long invoiceId; @ColumnInfo(name = "amount") public long amount; @ColumnInfo(name = "date") public long date; }
59. @Entity(tableName = "Invoices") public class InvoiceData { @PrimaryKey @ColumnInfo(name = "id") public long id; @ColumnInfo(name = "invoice_no") public String invoiceNo; public long amountGross; public long vatRate; // … @OneToMany public List<AdvancePaymentData> advancePayments; } @Entity(tableName = "AdvancePayments") public class AdvancePaymentData { @PrimaryKey @ColumnInfo(name = "id") public long id; @ColumnInfo(name = "invoice_id") public long invoiceId; @ColumnInfo(name = "amount") public long amount; @ColumnInfo(name = "date") public long date; }
60. @Entity(tableName = "Invoices") public class InvoiceData { @PrimaryKey @ColumnInfo(name = "id") public long id; @ColumnInfo(name = "invoice_no") public String invoiceNo; public long amountGross; public long vatRate; // … } @Entity(tableName = "AdvancePayments") public class AdvancePaymentData { @PrimaryKey @ColumnInfo(name = "id") public long id; @ColumnInfo(name = "invoice_id") public long invoiceId; @ColumnInfo(name = "amount") public long amount; @ColumnInfo(name = "date") public long date; }
61. @Entity(tableName = "Invoices") public class InvoiceData { @PrimaryKey @ColumnInfo(name = "id") public long id; @ColumnInfo(name = "invoice_no") public String invoiceNo; public long amountGross; public long vatRate; // … } @Entity(tableName = "AdvancePayments", foreignKeys = @ForeignKey( entity = InvoiceData.class, parentColumns = "id", childColumns = "invoice_id", onDelete = ForeignKey.CASCADE ) ) public class AdvancePaymentData { @PrimaryKey @ColumnInfo(name = "id") public long id; @ColumnInfo(name = "invoice_id") public long invoiceId; ...
62. @Entity(tableName = "Invoices") public class InvoiceData { @PrimaryKey @ColumnInfo(name = "id") public long id; @ColumnInfo(name = "invoice_no") public String invoiceNo; public long amountGross; public long vatRate; // … } @Entity(tableName = "AdvancePayments", foreignKeys = @ForeignKey( entity = InvoiceData.class, parentColumns = "id", childColumns = "invoice_id", onDelete = ForeignKey.CASCADE ) ) public class AdvancePaymentData { @PrimaryKey @ColumnInfo(name = "id") public long id; @ColumnInfo(name = "invoice_id") public long invoiceId; ...
63. @Entity(tableName = "Invoices") public class InvoiceData { @PrimaryKey @ColumnInfo(name = "id") public long id; @ColumnInfo(name = "invoice_no") public String invoiceNo; public long amountGross; public long vatRate; // … } @Entity(tableName = "AdvancePayments", foreignKeys = @ForeignKey( entity = InvoiceData.class, parentColumns = "id", childColumns = "invoice_id", onDelete = ForeignKey.CASCADE ) ) public class AdvancePaymentData { @PrimaryKey @ColumnInfo(name = "id") public long id; @ColumnInfo(name = "invoice_id") public long invoiceId; ...
64. @Entity(tableName = "Invoices") public class InvoiceData { @PrimaryKey @ColumnInfo(name = "id") public long id; @ColumnInfo(name = "invoice_no") public String invoiceNo; public long amountGross; public long vatRate; // … } @Entity(tableName = "AdvancePayments", foreignKeys = @ForeignKey( entity = InvoiceData.class, parentColumns = "id", childColumns = "invoice_id", onDelete = ForeignKey.CASCADE ) ) public class AdvancePaymentData { @PrimaryKey @ColumnInfo(name = "id") public long id; @ColumnInfo(name = "invoice_id") public long invoiceId; ...
65. @Entity(tableName = "Invoices") public class InvoiceData { @PrimaryKey @ColumnInfo(name = "id") public long id; @ColumnInfo(name = "invoice_no") public String invoiceNo; public long amountGross; public long vatRate; // … } @Entity(tableName = "AdvancePayments", foreignKeys = @ForeignKey( entity = InvoiceData.class, parentColumns = "id", childColumns = "invoice_id", onDelete = ForeignKey.CASCADE ) ) public class AdvancePaymentData { @PrimaryKey @ColumnInfo(name = "id") public long id; @ColumnInfo(name = "invoice_id") public long invoiceId; ...
66. Embedding POJOs in entities
67. @Entity(tableName = "Invoices") public class InvoiceData { // … @ColumnInfo(name = "amount_gross") public long amountGross; @ColumnInfo(name = "amount_net") public long amountNet; @ColumnInfo public String currency; @ColumnInfo(name = "vat_rate") public long vatRate; @ColumnInfo(name = "vat_amount") public long vatAmount; // … }
68. @Entity(tableName = "Invoices") public class InvoiceData { // … @ColumnInfo(name = "amount_gross") public long amountGross; @ColumnInfo(name = "amount_net") public long amountNet; @ColumnInfo public String currency; @ColumnInfo(name = "vat_rate") public long vatRate; @ColumnInfo(name = "vat_amount") public long vatAmount; // … } public class PriceData { @ColumnInfo(name = "amount_gross") public long amountGross; @ColumnInfo(name = "amount_net") public long amountNet; @ColumnInfo public String currency; @ColumnInfo(name = "vat_rate") public long vatRate; @ColumnInfo(name = "vat_amount") public long vatAmount; }
69. @Entity(tableName = "Invoices") public class InvoiceData { // … @ColumnInfo(name = "amount_gross") public long amountGross; @ColumnInfo(name = "amount_net") public long amountNet; @ColumnInfo public String currency; @ColumnInfo(name = "vat_rate") public long vatRate; @ColumnInfo(name = "vat_amount") public long vatAmount; // … } public class PriceData { @ColumnInfo(name = "amount_gross") public long amountGross; @ColumnInfo(name = "amount_net") public long amountNet; @ColumnInfo public String currency; @ColumnInfo(name = "vat_rate") public long vatRate; @ColumnInfo(name = "vat_amount") public long vatAmount; }
70. @Entity(tableName = "Invoices") public class InvoiceData { // … @Embedded public String priceData; // … } public class PriceData { @ColumnInfo(name = "amount_gross") public long amountGross; @ColumnInfo(name = "amount_net") public long amountNet; @ColumnInfo public String currency; @ColumnInfo(name = "vat_rate") public long vatRate; @ColumnInfo(name = "vat_amount") public long vatAmount; }
71. Storing data types not supported by SQLite
72. @Entity(tableName = "Invoices") public class InvoiceData { // … public String invoiceStatus; // … }
73. @Entity(tableName = "Invoices") public class InvoiceData { // … public String invoiceStatus; // … } public enum InvoiceStatus { PAID(1, "Z"), OVERDUE(2, "P"), STORNO(3, "Q"), UNKNOWN(4, "UNKNOWN"); }
74. @Entity(tableName = "Invoices") public class InvoiceData { // … public String invoiceStatus; // … } public enum InvoiceStatus { PAID(1, "Z"), OVERDUE(2, "P"), STORNO(3, "Q"), UNKNOWN(4, "UNKNOWN"); }
75. @Entity(tableName = "Invoices") public class InvoiceData { // … public String invoiceStatus; // … } public enum InvoiceStatus { PAID(1, "Z"), OVERDUE(2, "P"), STORNO(3, "Q"), UNKNOWN(4, "UNKNOWN"); }
76. @Entity(tableName = "Invoices") public class InvoiceData { // … public InvoiceStatus invoiceStatus; // … } public enum InvoiceStatus { PAID(1, "Z"), OVERDUE(2, "P"), STORNO(3, "Q"), UNKNOWN(4, "UNKNOWN"); }
77. public class RoomTypeConverters { @TypeConverter public InvoiceStatus fromDatabase(Long value) { if (value == null) { return null; } else { return InvoiceStatus.fromDatabaseId(value); } } @TypeConverter public Long toDatabase(InvoiceStatus invoiceStatus) { if (invoiceStatus == null) { return null; } else { return invoiceStatus.getDatabaseId(); } } }
78. public class RoomTypeConverters { @TypeConverter public InvoiceStatus fromDatabase(Long value) { if (value == null) { return null; } else { return InvoiceStatus.fromDatabaseId(value); } } @TypeConverter public Long toDatabase(InvoiceStatus invoiceStatus) { if (invoiceStatus == null) { return null; } else { return invoiceStatus.getDatabaseId(); } } }
79. public class RoomTypeConverters { @TypeConverter public InvoiceStatus fromDatabase(Long value) { if (value == null) { return null; } else { return InvoiceStatus.fromDatabaseId(value); } } @TypeConverter public Long toDatabase(InvoiceStatus invoiceStatus) { if (invoiceStatus == null) { return null; } else { return invoiceStatus.getDatabaseId(); } } }
80. public class RoomTypeConverters { @TypeConverter public InvoiceStatus fromDatabase(Long value) { if (value == null) { return null; } else { return InvoiceStatus.fromDatabaseId(value); } } @TypeConverter public Long toDatabase(InvoiceStatus invoiceStatus) { if (invoiceStatus == null) { return null; } else { return invoiceStatus.getDatabaseId(); } } }
81. Recap • @Entity to declare models stored in database • Add some “structure” with @Embedded • Support all possible data types with @TypeConverter • Add relation between entities with @ForeignKey • … but not as cool as @OneToMany entities in Requery • BTW all above features are available in Requery
82. Database object to glue everything together
83. Room public abstract class FaktoriaDatabase extends RoomDatabase { }
84. Room @Database() public abstract class FaktoriaDatabase extends RoomDatabase { }
85. Room @Database( entities = {InvoiceData.class, AdvancePaymentData.class}, ) public abstract class FaktoriaDatabase extends RoomDatabase { }
86. Room @Database( entities = {InvoiceData.class, AdvancePaymentData.class}, version = 4, ) public abstract class FaktoriaDatabase extends RoomDatabase { }
87. Room @Database( entities = {InvoiceData.class, AdvancePaymentData.class}, version = 4, exportSchema = false ) public abstract class FaktoriaDatabase extends RoomDatabase { }
88. Room @Database( entities = {InvoiceData.class, AdvancePaymentData.class}, version = 4, exportSchema = false ) @TypeConverters({RoomTypeConverters.class}) public abstract class FaktoriaDatabase extends RoomDatabase { }
89. Room @Database( entities = {InvoiceData.class, AdvancePaymentData.class}, version = 4, exportSchema = false ) @TypeConverters({RoomTypeConverters.class}) public abstract class FaktoriaDatabase extends RoomDatabase { public abstract InvoiceDataDao invoiceDataDao(); }
90. Room @Database( entities = {InvoiceData.class, AdvancePaymentData.class}, version = 4, exportSchema = false ) @TypeConverters({RoomTypeConverters.class}) public abstract class FaktoriaDatabase extends RoomDatabase { public abstract InvoiceDataDao invoiceDataDao(); public abstract AdvancePaymentDataDao advancePaymentDataDao(); }
91. Room @Database( entities = {InvoiceData.class, AdvancePaymentData.class}, version = 4, exportSchema = false ) @TypeConverters({RoomTypeConverters.class}) public abstract class FaktoriaDatabase extends RoomDatabase { public abstract InvoiceDataDao invoiceDataDao(); public abstract AdvancePaymentDataDao advancePaymentDataDao(); }
92. Recap • Database class to glue things together • Room generates code to open/create database file, create tables, do migrations, etc. • With Requery done in a similar fashion but with less annotations and more Java code
93. Making queries with help of DAO
94. database
95. database
96. database app
97. database app DAO
98. database app DAO Java
99. database app DAO SQL Java
100. database app DAO SQL Java data mapping
101. database app DAO SQL Java data mapping POJO
102. public interface MyDao { }
103. @Dao public interface MyDao { }
104. @Dao public interface MyDao { InvoiceData getInvoice(long invoiceId); }
105. @Dao public interface MyDao { @Query("SELECT * FROM Invoices WHERE id = :invoiceId") InvoiceData getInvoice(long invoiceId); }
106. @Dao public interface MyDao { @Query("SELECT * FROM Invoices WHERE id = :invoiceId") InvoiceData getInvoice(long invoiceId); } public Maybe<InvoiceData> getInvoice(long invoiceId) { return database .select(InvoiceData.class) .where(InvoiceData.ID.eq(invoiceId)) .get() .maybe(); }
107. @Dao public interface MyDao { @Query("SELECT * FROM Invoices WHERE id = :invoiceId") InvoiceData getInvoice(long invoiceId); } public Maybe<InvoiceData> getInvoice(long invoiceId) { return database .select(InvoiceData.class) .where(InvoiceData.ID.eq(invoiceId)) .get() .maybe(); }
108. @Dao public interface MyDao { @Query("SELECT * FROM Invoices WHERE id = :invoiceId") InvoiceData getInvoice(long invoiceId); }
109. @Dao public interface MyDao { @Query("SELECT * FROM Invoices") List<InvoiceData> getInvoices(); }
110. @Dao public interface MyDao { @Query("SELECT * FROM Invoices WHERE id = :invoiceId") Single<InvoiceData> getInvoice(long invoiceId); }
111. @Dao public interface MyDao { @Query("SELECT * FROM Invoices WHERE id = :invoiceId") Flowable<InvoiceData> getInvoice(long invoiceId); }
112. @Dao public interface MyDao { @Query("SELECT * FROM Invoices WHERE id = :invoiceId") Single<InvoiceData> getInvoice(long invoiceId); @Query("SELECT * FROM Invoices WHERE id = :invoiceId") Flowable<InvoiceData> getInvoice2(long invoiceId); }
113. @Dao public interface MyDao { @Query("SELECT * FROM Invoices WHERE id = :invoiceId") Single<InvoiceData> getInvoice(long invoiceId); @Query("SELECT * FROM Invoices WHERE id = :invoiceId") Flowable<InvoiceData> getInvoiceAndListenForUpdates(long invoiceId); }
114. @Dao public interface MyDao { @Query("SELECT * FROM Invoices WHERE id = :invoiceId") Single<InvoiceData> getInvoice(long invoiceId); @Query("SELECT * FROM Invoices WHERE id = :invoiceId") Flowable<List<InvoiceData>> getInvoiceAndListenForUpdates(long invoiceId); }
115. @Dao public interface MyDao { @Query("SELECT * FROM Invoices WHERE id = :invoiceId") Single<InvoiceData> getInvoice(long invoiceId); @Query("SELECT * FROM Invoices WHERE id = :invoiceId") Flowable<List<InvoiceData>> getInvoiceAndListenForUpdates(long invoiceId); @Query("SELECT * FROM Invoices") Flowable<List<InvoiceData>> getAllInvoicesAndListenForUpdates(); }
116. @Dao public interface MyDao { @Update void updateInvoice(InvoiceData invoice); }
117. @Dao public interface MyDao { @Update void updateInvoice(InvoiceData invoice); @Insert void insertInvoice(InvoiceData invoice); }
118. @Dao public interface MyDao { @Update void updateInvoice(InvoiceData invoice); @Insert void insertInvoice(InvoiceData invoice); @Insert(onConflict = OnConflictStrategy.REPLACE) void upsertInvoice(InvoiceData invoice); }
119. Relations with queries
120. @Dao public interface MyDao { @Query("SELECT * FROM book " + "INNER JOIN loan ON loan.book_id = book.id " + "INNER JOIN user ON user.id = loan.user_id " + "WHERE user.name LIKE :userName") List<Book> findBooksBorrowedByNameSync(String userName); }
121. Fun with queries 0
123. @Dao public interface InvoiceDataDao { @Query("SELECT * FROM Invoices") Flowable<List<InvoiceData>> getInvoices(); }
124. @Dao public interface InvoiceDataDao { @Query("SELECT * FROM Invoices") Flowable<List<InvoiceOverviewData>> getInvoices(); }
125. @Dao public interface InvoiceDataDao { @Query("SELECT * FROM Invoices") Flowable<List<InvoiceOverviewData>> getInvoices(); } public class InvoiceOverviewData { // … @ColumnInfo(name = "invoice_no") private String invoiceNo; @ColumnInfo(name = "amount_gross") private long amountGross; @ColumnInfo(name = "debtor_name") private String debtorName; // … }
126. Warning:(25, 41) The query returns some columns [purchase_date, funding_end_date, contract_id, debtor_address, debtor_nip, debtor_regon, creditor_name, creditor_address, creditor_nip, creditor_regon, correction, sell_date, import_date, amount_net, currency, vat_rate, vat_amount] which are not use by online.faktoria.data.invoice.model.InvoiceOverviewData. You can use @ColumnInfo annotation on the fields to specify the mapping. You can suppress this warning by annotating the method with @SuppressWarnings(RoomWarnings.CURSOR_MISMATCH). Columns returned by the query: id, invoice_no, purchase_date, funding_end_date, contract_id, debtor_name, debtor_address, debtor_nip, debtor_regon, creditor_name, creditor_address, creditor_nip, creditor_regon, correction, sell_date, maturity_date, invoice_status_code, import_date, amount_gross, amount_net, currency, vat_rate, vat_amount. Fields in online.faktoria.data.invoice.model.InvoiceOverviewData: id, invoice_no, amount_gross, debtor_name, maturity_date, invoice_status_code.
127. Warning:(25, 41) The query returns some columns [...] which are not use by InvoiceOverviewData. You can use @ColumnInfo annotation on the fields to specify the mapping. You can suppress this warning by annotating the method with @SuppressWarnings(RoomWarnings.CURSOR_MISMATCH). Columns returned by the query: ... Fields in InvoiceOverviewData: ...
128. @Dao public interface InvoiceDataDao { @Query("SELECT * FROM Invoices") Flowable<List<InvoiceOverviewData>> getInvoices(); } public class InvoiceOverviewData { // … @ColumnInfo(name = "invoice_no") private String invoiceNo; @ColumnInfo(name = "amount_gross") private long amountGross; @ColumnInfo(name = "debtor_name") private String debtorName; // … }
129. @Dao public interface InvoiceDataDao { @Query("SELECT * FROM Invoices") Flowable<List<InvoiceOverviewData>> getInvoices(); } public class InvoiceOverviewData { // … @ColumnInfo(name = "invoice_no") private String invoiceNo; @ColumnInfo(name = "amount_gross") private long amountGross; @ColumnInfo(name = "debtor_name") private String debtorName; // … }
130. @Dao public interface InvoiceDataDao { @Query("SELECT id, invoice_no, amount_gross, debtor_name, debtor_name, ” + “maturity_date, invoice_status_code FROM Invoices") Flowable<List<InvoiceOverviewData>> getInvoices(); } public class InvoiceOverviewData { // … @ColumnInfo(name = "invoice_no") private String invoiceNo; @ColumnInfo(name = "amount_gross") private long amountGross; @ColumnInfo(name = "debtor_name") private String debtorName; // … }
131. Fun with queries 1
133. @Dao public interface InvoiceDataDao { Flowable<InvoiceAndAdvancePaymentsData> getInvoice(long invoiceId); }
134. @Dao public interface InvoiceDataDao { Flowable<InvoiceAndAdvancePaymentsData> getInvoice(long invoiceId); } public class InvoiceAndAdvancePaymentsData { public InvoiceData invoice; public List<AdvancePaymentData> advancePayments; }
135. @Dao public interface InvoiceDataDao { @Query("SELECT * FROM Invoices WHERE id = :invoiceId") Flowable<InvoiceAndAdvancePaymentsData> getInvoice(long invoiceId); } public class InvoiceAndAdvancePaymentsData { public InvoiceData invoice; public List<AdvancePaymentData> advancePayments; }
136. @Dao public interface InvoiceDataDao { @Query("SELECT * FROM Invoices WHERE id = :invoiceId") Flowable<InvoiceAndAdvancePaymentsData> getInvoice(long invoiceId); } public class InvoiceAndAdvancePaymentsData { @Embedded public InvoiceData invoice; public List<AdvancePaymentData> advancePayments; }
137. @Dao public interface InvoiceDataDao { @Query("SELECT * FROM Invoices WHERE id = :invoiceId") Flowable<InvoiceAndAdvancePaymentsData> getInvoice(long invoiceId); } public class InvoiceAndAdvancePaymentsData { @Embedded public InvoiceData invoice; @Relation(parentColumn = "id", entityColumn = "invoice_id") public List<AdvancePaymentData> advancePayments; }
138. Recap • Have to write SQL queries by hand … and not in Requery case • Synchronous writes and asynchronous reads … and however you like with Requery • Can do advanced queries with SQL JOINs, @Relation, or custom POJOs to map results to
139. Testing
140. @RunWith(AndroidJUnit4.class) public class RoomTest { @Before public void setup() { } @Before public void tearDown() { } }
141. @RunWith(AndroidJUnit4.class) public class RoomTest { @Rule public InstantTaskExecutorRule instantTaskExecutorRule = new InstantTaskExecutorRule(); @Before public void setup() { } @Before public void tearDown() { } }
142. @RunWith(AndroidJUnit4.class) public class RoomTest { @Rule public InstantTaskExecutorRule instantTaskExecutorRule = new InstantTaskExecutorRule(); private MyDatabase database; @Before public void setup() { } @Before public void tearDown() { } }
143. @RunWith(AndroidJUnit4.class) public class RoomTest { @Rule public InstantTaskExecutorRule instantTaskExecutorRule = new InstantTaskExecutorRule(); private MyDatabase database; @Before public void setup() { Context context = InstrumentationRegistry.getTargetContext(); database = Room .inMemoryDatabaseBuilder(context, MyDatabase.class) .build(); } @Before public void tearDown() { } }
144. @RunWith(AndroidJUnit4.class) public class RoomTest { @Rule public InstantTaskExecutorRule instantTaskExecutorRule = new InstantTaskExecutorRule(); private MyDatabase database; @Before public void setup() { Context context = InstrumentationRegistry.getTargetContext(); database = Room .inMemoryDatabaseBuilder(context, MyDatabase.class) .build(); } @Before public void tearDown() { database.close(); } }
145. @RunWith(AndroidJUnit4.class) public class RoomTest { @Rule public InstantTaskExecutorRule instantTaskExecutorRule = new InstantTaskExecutorRule(); private MyDatabase database; private ProjectDao projectDao; private TaskDao taskDao; @Before public void setup() { Context context = InstrumentationRegistry.getTargetContext(); database = Room .inMemoryDatabaseBuilder(context, MyDatabase.class) .build(); } // …
146. @RunWith(AndroidJUnit4.class) public class RoomTest { @Rule public InstantTaskExecutorRule instantTaskExecutorRule = new InstantTaskExecutorRule(); private MyDatabase database; private ProjectDao projectDao; private TaskDao taskDao; @Before public void setup() { Context context = InstrumentationRegistry.getTargetContext(); database = Room .inMemoryDatabaseBuilder(context, MyDatabase.class) .build(); projectDao = database.projectDao(); taskDao = database.taskDao(); } // …
147. @Test public void shouldEmitNewTaskForProject() { // given projectDao.insertProject(project1).test(); // when TestSubscriber<List<Task>> testSubscriber = taskDao.getTaskForProject(project1) .test(); // then testSubscriber.assertNotComplete(); testSubscriber.assertNoErrors(); assertEquals(1, testSubscriber.values().size()); // [ [] ] assertEquals(0, testSubscriber.values().get(0).size()); // [ [] ] // ...
148. // ... // when task1.setProject(project1); taskDao.insertTask(task1).test(); // then testSubscriber.assertNotComplete(); testSubscriber.assertNoErrors(); assertEquals(2, testSubscriber.values().size()); assertEquals(0, testSubscriber.values().get(0).size()); // [ [] ] assertEquals(1, testSubscriber.values().get(1).size()); // [ [ Task1 ] ] }
149. Migrations and migration testing
150. @Entity(tableName = "Invoices") public class InvoiceData { @PrimaryKey @ColumnInfo(name = "id") public long id; @ColumnInfo(name = "invoice_no") public String invoiceNo; public long amountGross; public long vatRate; // … }
151. @Entity(tableName = "Invoices") public class InvoiceData { @PrimaryKey @ColumnInfo(name = "id") public long id; @ColumnInfo(name = "invoice_no") public String invoiceNo; public long amountGross; public long vatRate; // … @ColumnInfo(name = "new_field") public long newField; }
152. CREATE TABLE `Invoices` ( `id` INTEGER NOT NULL, `invoice_no` TEXT, `purchase_date` INTEGER NOT NULL, // … }
153. CREATE TABLE `Invoices` ( `id` INTEGER NOT NULL, `invoice_no` TEXT, `purchase_date` INTEGER NOT NULL, // … } CREATE TABLE `Invoices` ( `id` INTEGER NOT NULL, `invoice_no` TEXT, `purchase_date` INTEGER NOT NULL, // … new_field INTEGER NOT NULL DEFAULT 4 }
154. CREATE TABLE `Invoices` ( `id` INTEGER NOT NULL, `invoice_no` TEXT, `purchase_date` INTEGER NOT NULL, // … } CREATE TABLE `Invoices` ( `id` INTEGER NOT NULL, `invoice_no` TEXT, `purchase_date` INTEGER NOT NULL, // … new_field INTEGER NOT NULL DEFAULT 4 }
155. java.lang.IllegalStateException: Room cannot verify the data integrity. Looks like you’ve changed schema but forgot to update the version number. You can simply fix this by increasing the version number.
156. @Database( entities = {InvoiceData.class, AdvancePaymentData.class}, version = 4, exportSchema = false ) @TypeConverters({RoomTypeConverters.class}) public abstract class FaktoriaDatabase extends RoomDatabase { public abstract InvoiceDataDao invoiceDataDao(); public abstract AdvancePaymentDataDao advancePaymentDataDao(); }
157. @Database( entities = {InvoiceData.class, AdvancePaymentData.class}, version = 5, exportSchema = false ) @TypeConverters({RoomTypeConverters.class}) public abstract class FaktoriaDatabase extends RoomDatabase { public abstract InvoiceDataDao invoiceDataDao(); public abstract AdvancePaymentDataDao advancePaymentDataDao(); }
158. java.lang.IllegalStateException: A migration from 4 to 5 is necessary. Please provide a Migration in the builder or call fallbackToDestructiveMigration in the builder in which case Room will re-create all of the tables.
159. static final Migration MIGRATION_4_5 = new Migration(4, 5) { @Override public void migrate(SupportSQLiteDatabase database) { database.execSQL( "ALTER TABLE Invoices ADD COLUMN `new_field` INTEGER NOT NULL DEFAULT 0" ); } };
160. static final Migration MIGRATION_4_5 = new Migration(4, 5) { @Override public void migrate(SupportSQLiteDatabase database) { database.execSQL( "ALTER TABLE Invoices ADD COLUMN `new_field` INTEGER NOT NULL DEFAULT 0" ); } };
161. static final Migration MIGRATION_4_5 = new Migration(4, 5) { @Override public void migrate(SupportSQLiteDatabase database) { database.execSQL( "ALTER TABLE Invoices ADD COLUMN `new_field` INTEGER NOT NULL DEFAULT 0" ); } }; @Provides @Singleton FaktoriaDatabase provideDatabase(@NonNull final Context context) { return Room .databaseBuilder( context.getApplicationContext(), FaktoriaDatabase.class, "database-name" ) .build(); }
162. static final Migration MIGRATION_4_5 = new Migration(4, 5) { @Override public void migrate(SupportSQLiteDatabase database) { database.execSQL( "ALTER TABLE Invoices ADD COLUMN `new_field` INTEGER NOT NULL DEFAULT 0" ); } }; @Provides @Singleton FaktoriaDatabase provideDatabase(@NonNull final Context context) { return Room .databaseBuilder( context.getApplicationContext(), FaktoriaDatabase.class, "database-name" ) .addMigrations(MIGRATION_4_5) .build(); }
163. static final Migration MIGRATION_4_5 = new Migration(4, 5) { @Override public void migrate(SupportSQLiteDatabase database) { database.execSQL( "ALTER TABLE Invoices ADD COLUMN `new_field` INTEGER NOT NULL DEFAULT 0" ); } }; @Provides @Singleton FaktoriaDatabase provideDatabase(@NonNull final Context context) { return Room .databaseBuilder( context.getApplicationContext(), FaktoriaDatabase.class, "database-name" ) .addMigrations(MIGRATION_4_5) .build(); }
164. Migrations testing
165. Setup 1. Don’t turn off schema export ;-) 2. Add few things to build.gradle file a. Schema files location for tests b. Schema export for annotation processor c. One or two extra dependencies
166. @RunWith(AndroidJUnit4.class) public class ExampleInstrumentedTest { // ... }
167. @RunWith(AndroidJUnit4.class) public class ExampleInstrumentedTest { private static final String TEST_DB_NAME = "test-database"; @Rule public MigrationTestHelper migrationTestHelper = new MigrationTestHelper( InstrumentationRegistry.getInstrumentation(), FaktoriaDatabase.class.getCanonicalName(), new FrameworkSQLiteOpenHelperFactory() ); // ... }
168. @RunWith(AndroidJUnit4.class) public class ExampleInstrumentedTest { private static final String TEST_DB_NAME = "test-database"; @Rule public MigrationTestHelper migrationTestHelper = new MigrationTestHelper( InstrumentationRegistry.getInstrumentation(), FaktoriaDatabase.class.getCanonicalName(), new FrameworkSQLiteOpenHelperFactory() ); // ... }
169. @RunWith(AndroidJUnit4.class) public class ExampleInstrumentedTest { // … private void insertInvoice(final SupportSQLiteDatabase db) { final ContentValues values = new ContentValues(); values.put("id", 1); values.put("invoice_no", "Invoice NO/123"); values.put("funding_end_date", 1); values.put("purchase_date", 1); values.put("sell_date", 1); values.put("maturity_date", 1); values.put("import_date", 1); values.put("correction", false); values.put("contract_id", 1); db.insert("Invoices", SQLiteDatabase.CONFLICT_REPLACE, values); } // … }
170. @Test public void testMigrationFrom4to5() throws IOException { final SupportSQLiteDatabase db = migrationTestHelper.createDatabase(TEST_DB_NAME, 4); }
171. @Test public void testMigrationFrom4to5() throws IOException { final SupportSQLiteDatabase db = migrationTestHelper.createDatabase(TEST_DB_NAME, 4); insertInvoice(db); }
172. @Test public void testMigrationFrom4to5() throws IOException { final SupportSQLiteDatabase db = migrationTestHelper.createDatabase(TEST_DB_NAME, 4); insertInvoice(db); migrationTestHelper.runMigrationsAndValidate(TEST_DB_NAME, 5, true, MIGRATION_4_5); }
173. @Test public void testMigrationFrom4to5() throws IOException { final SupportSQLiteDatabase db = migrationTestHelper.createDatabase(TEST_DB_NAME, 4); insertInvoice(db); migrationTestHelper.runMigrationsAndValidate(TEST_DB_NAME, 5, true, MIGRATION_4_5); final FaktoriaDatabase database = Room .databaseBuilder(..., FaktoriaDatabase.class, TEST_DB_NAME) .addMigrations(MIGRATION_4_5) .build(); migrationTestHelper.closeWhenFinished(database); }
174. @Test public void testMigrationFrom4to5() throws IOException { final SupportSQLiteDatabase db = migrationTestHelper.createDatabase(TEST_DB_NAME, 4); insertInvoice(db); migrationTestHelper.runMigrationsAndValidate(TEST_DB_NAME, 5, true, MIGRATION_4_5); final FaktoriaDatabase database = Room .databaseBuilder(..., FaktoriaDatabase.class, TEST_DB_NAME) .addMigrations(MIGRATION_4_5) .build(); migrationTestHelper.closeWhenFinished(database); InvoiceData invoiceAfterMigration = database.invoiceDataDao() .getInvoice(1).blockingGet(); }
175. @Test public void testMigrationFrom4to5() throws IOException { final SupportSQLiteDatabase db = migrationTestHelper.createDatabase(TEST_DB_NAME, 4); insertInvoice(db); migrationTestHelper.runMigrationsAndValidate(TEST_DB_NAME, 5, true, MIGRATION_4_5); final FaktoriaDatabase database = Room .databaseBuilder(..., FaktoriaDatabase.class, TEST_DB_NAME) .addMigrations(MIGRATION_4_5) .build(); migrationTestHelper.closeWhenFinished(database); InvoiceData invoiceAfterMigration = database.invoiceDataDao() .getInvoice(1).blockingGet(); assertEquals(4, invoiceAfterMigration.newField); }
176. @Test public void testMigrationFrom4to5() throws IOException { final SupportSQLiteDatabase db = migrationTestHelper.createDatabase(TEST_DB_NAME, 4); insertInvoice(db); migrationTestHelper.runMigrationsAndValidate(TEST_DB_NAME, 5, true, MIGRATION_4_5); final FaktoriaDatabase database = Room .databaseBuilder(..., FaktoriaDatabase.class, TEST_DB_NAME) .addMigrations(MIGRATION_4_5) .build(); migrationTestHelper.closeWhenFinished(database); InvoiceData invoiceAfterMigration = database.invoiceDataDao() .getInvoice(1).blockingGet(); assertEquals(4, invoiceAfterMigration.newField); }
177. Room TL;DR • just use it, if you were using low level APIs • can be attractive for requery.io and greendao users • will definitely improve over time by adding missing features (from requery.io ;-) • … and there is The Florina Factor • https://www.youtube.com/watch?v=QrbhPcbZv0I • https://medium.com/google-developers/7-steps-to-room-27a5fe5f99b2 • https://medium.com/google-developers/room-rxjava-acb0cd4f3757 • https://github.com/googlesamples/android-architecture-components
180. Q&A Aleksander Piotrowski @pelotasplus