Models
In DBFlow we dont have any restrictions on what your table class is. We do, however if you use Java, we recommend you subclass BaseModel
on
your highest-order base-class, which provides a default implementation for you.
When using regular models:
FlowManager.getModelAdapter(MyTable.class).save(myTableObject);
When using BaseModel
, it is much cleaner:
myTableObject.save();
if you use Kotlin, you can add the kotlin extensions to your project use them as extension methods:
myTableObject.save()
Columns
By default, DBFlow lazily looks for columns. This means that they all must contain either @PrimaryKey
, @Column
, or @ForeignKey
to be used in tables.
If you wish to make it simpler and include all fields in a class, set @Table(allFields = true)
.
However this still requires you to specify at least one @PrimaryKey
field. You
can then explicitly ignore fields via the @ColumnIgnore
annotation.
Columns can be public
, package-private, or private
.
private
fields must come with public
java-bean-style getters and setters.
Here is an example of a "nice" private
field:
@Table(database = AppDatabase.class)
public class Dog {
@PrimaryKey
private String name;
public void setName(String name) {
this.name = name;
}
public String getName() {
return name;
}
}
@Table(database = AppDatabase.class)
public class Dog(@Primary var name: String? = null)
Columns have a wide-range of supported types in the Model
classes:
Supported Types:
- all java primitives including
char
,byte
,short
, andboolean
. - All java boxed primitive classes
- String, Date, java.sql.Date, Calendar, Blob, Boolean
- Custom data types via a TypeConverter
Model
as fields, but only as@PrimaryKey
and/or@ForeignKey
@ColumnMap
objects that flatten an object into the current table. Just like a@ForeignKey
, but without requiring a separate table. (4.1.0+). Avoid nesting more than one object, as the column count could get out of control.
Unsupported Types:
List<T>
: List columns are not supported and not generally proper for a relational database. However, you can get away with a non-genericList
column via aTypeConverter
. But again, avoid this if you can.- Anything that is generically typed (even with an associated
TypeConverter
). If you need to include the field, subclass the generic object and provide aTypeConverter
.
Inherited Columns
Since we don't require extension on BaseModel
directly, tables can extend non-model classes and inherit their fields directly (given proper accessibility) via the @InheritedColumn
annotation (or @InheritedPrimaryKey
for primary keys):
@Table(database = AppDatabase.class,
inheritedColumns = {@InheritedColumn(column = @Column, fieldName = "name"),
@InheritedColumn(column = @Column, fieldName = "number")},
inheritedPrimaryKeys = {@InheritedPrimaryKey(column = @Column,
primaryKey = @PrimaryKey,
fieldName = "inherited_primary_key")})
public class InheritorModel extends InheritedModel implements Model {
Primary Keys
DBFlow supports multiple primary keys, right out of the box. Simply create a table with multiple @PrimaryKey
:
@Table(database = AppDatabase.class)
public class Dog extends BaseModel {
@PrimaryKey
String name;
@PrimaryKey
String breed;
}
@Table(database = AppDatabase::class)
class Dog(@PrimaryKey var name: String? = null,
@PrimaryKey var breed: String? = null)
If we want an auto-incrementing key, you specify @PrimaryKey(autoincrement = true)
, but only one of these kind can exist in a table and you cannot mix with regular primary keys.
Unique Columns
DBFlow has support for SQLite UNIQUE
constraint (here for documentation)[http://www.tutorialspoint.com/sqlite/sqlite_constraints.htm].
Add @Unique
annotation to your existing @Column
and DBFlow adds it as a constraint when
the database table is first created. This means that once it is created you should not change or modify this.
We can also support multiple unique clauses in order to ensure any combination of fields are unique. For example:
To generate this in the creation query:
UNIQUE('name', 'number') ON CONFLICT FAIL, UNIQUE('name', 'address') ON CONFLICT ROLLBACK
We declare the annotations as such:
@Table(database = AppDatabase.class,
uniqueColumnGroups = {@UniqueGroup(groupNumber = 1, uniqueConflict = ConflictAction.FAIL),
@UniqueGroup(groupNumber = 2, uniqueConflict = ConflictAction.ROLLBACK))
public class UniqueModel {
@PrimaryKey
@Unique(unique = false, uniqueGroups = {1,2})
String name;
@Column
@Unique(unique = false, uniqueGroups = 1)
String number;
@Column
@Unique(unique = false, uniqueGroups = 2)
String address;
}
The groupNumber
within each defined uniqueColumnGroups
with an associated @Unique
column. We need to specify unique=false
for any column used in a group so we expect the column to be part of a group. If true as well, the column will also alone be unique.
Default Values
DBFlow supports default values in a slighty different way that SQLite does. Since we do not know
exactly the intention of missing data when saving a Model
, since we group all fields, defaultValue
specifies
a value that we replace when saving to the database when the value of the field is null
.
This feature only works on Boxed primitive and the DataClass
equivalent of objects (such as from TypeConverter), such as String, Integer, Long, Double, etc.
Note: If the DataClass
is a Blob
, unfortunately this will not work.
For Boolean
classes, use "1" for true, "0" for false.
@Column(defaultValue = "55")
Integer count;
@Column(defaultValue = "\"this is\"")
String test;
@Column(defaultValue = "1000L")
Date date;
@Column(defaultValue = "1")
Boolean aBoolean;
DBFlow inserts it's literal value into the ModelAdapter
for the table so any String
must be escaped.