Summary: Nested Classes | Constants | Methods | Inherited Methods

ColumnInfo

The android.arch Architecture Components packages are no longer maintained. They have been superseded by the corresponding androidx.* packages. See androidx.room.ColumnInfo instead.

public abstract @interface ColumnInfo
implements Annotation

android.arch.persistence.room.ColumnInfo

---

Allows specific customization about the column associated with this field.

For example, you can specify a column name for the field or change the column's type affinity.

Summary

Nested classes
@interface	ColumnInfo.Collate
@interface	ColumnInfo.SQLiteTypeAffinity The SQLite column type constants that can be used in typeAffinity()

Constants
int	BINARY Collation sequence for case-sensitive match.
int	BLOB Column affinity constant for binary data.
String	INHERIT_FIELD_NAME Constant to let Room inherit the field name as the column name.
int	INTEGER Column affinity constant for integers or booleans.
int	LOCALIZED Collation sequence that uses system's current locale.
int	NOCASE Collation sequence for case-insensitive match.
int	REAL Column affinity constant for floats or doubles.
int	RTRIM Collation sequence for case-sensitive match except that trailing space characters are ignored.
int	TEXT Column affinity constant for strings.
int	UNDEFINED Undefined type affinity.
int	UNICODE Collation sequence that uses Unicode Collation Algorithm.
int	UNSPECIFIED Collation sequence is not specified.

Public methods
int	collate() The collation sequence for the column, which will be used when constructing the database.
boolean	index() Convenience method to index the field.
String	name() Name of the column in the database.
int	typeAffinity() The type affinity for the column, which will be used when constructing the database.

Inherited methods
From interface java.lang.annotation.Annotation abstract Class<? extends Annotation> annotationType() abstract boolean equals(Object arg0) abstract int hashCode() abstract String toString()

Constants

BINARY

int BINARY

Collation sequence for case-sensitive match.

See also:

• collate()

Constant Value: 2 (0x00000002)

BLOB

int BLOB

Column affinity constant for binary data.

See also:

• typeAffinity()

Constant Value: 5 (0x00000005)

INHERIT_FIELD_NAME

String INHERIT_FIELD_NAME

Constant to let Room inherit the field name as the column name. If used, Room will use the field name as the column name.

Constant Value: "[field-name]"

INTEGER

int INTEGER

Column affinity constant for integers or booleans.

See also:

• typeAffinity()

Constant Value: 3 (0x00000003)

LOCALIZED

int LOCALIZED

Collation sequence that uses system's current locale.

See also:

• collate()

Constant Value: 5 (0x00000005)

NOCASE

int NOCASE

Collation sequence for case-insensitive match.

See also:

• collate()

Constant Value: 3 (0x00000003)

REAL

int REAL

Column affinity constant for floats or doubles.

See also:

• typeAffinity()

Constant Value: 4 (0x00000004)

RTRIM

int RTRIM

Collation sequence for case-sensitive match except that trailing space characters are ignored.

See also:

• collate()

Constant Value: 4 (0x00000004)

TEXT

int TEXT

Column affinity constant for strings.

See also:

• typeAffinity()

Constant Value: 2 (0x00000002)

UNDEFINED

int UNDEFINED

Undefined type affinity. Will be resolved based on the type.

See also:

• typeAffinity()

Constant Value: 1 (0x00000001)

UNICODE

int UNICODE

Collation sequence that uses Unicode Collation Algorithm.

See also:

• collate()

Constant Value: 6 (0x00000006)

UNSPECIFIED

int UNSPECIFIED

Collation sequence is not specified. The match will behave like BINARY.

See also:

• collate()

Constant Value: 1 (0x00000001)

Public methods

collate

int collate ()

The collation sequence for the column, which will be used when constructing the database.

The default value is UNSPECIFIED. In that case, Room does not add any collation sequence to the column, and SQLite treats it like BINARY.

Returns
int	The collation sequence of the column. This is either UNSPECIFIED, BINARY, NOCASE, RTRIM, LOCALIZED or UNICODE.

index

boolean index ()

Convenience method to index the field.

If you would like to create a composite index instead, see: Index.

Returns
boolean	True if this field should be indexed, false otherwise. Defaults to false.

name

String name ()

Name of the column in the database. Defaults to the field name if not set.

Returns
String	Name of the column in the database.

typeAffinity

int typeAffinity ()

The type affinity for the column, which will be used when constructing the database.

If it is not specified, the value defaults to UNDEFINED and Room resolves it based on the field's type and available TypeConverters.

See SQLite types documentation for details.

Returns
int	The type affinity of the column. This is either UNDEFINED, TEXT, INTEGER, REAL, or BLOB.

• Annotations

  • ColumnInfo
  • ColumnInfo.Collate
  • ColumnInfo.SQLiteTypeAffinity
  • Dao
  • Database
  • Delete
  • Embedded
  • Entity
  • ForeignKey
  • ForeignKey.Action
  • Ignore
  • Index
  • Insert
  • OnConflictStrategy
  • PrimaryKey
  • Query
  • RawQuery
  • Relation
  • SkipQueryVerification
  • Transaction
  • TypeConverter
  • TypeConverters
  • Update

• Classes

  • DatabaseConfiguration
  • InvalidationTracker
  • InvalidationTracker.Observer
  • Room
  • RoomDatabase
  • RoomDatabase.Builder
  • RoomDatabase.Callback
  • RoomDatabase.MigrationContainer
  • RoomWarnings
  • RxRoom

• Enums

  • RoomDatabase.JournalMode

• Exceptions

  • EmptyResultSetException