drift library Null safety

Classes

ArgumentsForBatchedStatement
Instruction to run a batched sql statement with the arguments provided.
BaseSelectStatement
The abstract base class for all select statements in the drift api. [...]
Batch
Contains operations to run queries in a batched mode. This can be much more efficient when running a lot of similar queries at the same time, making this api suitable for bulk updates.
BatchedStatements
Stores information needed to run batched statements in the order they were issued without preparing statements multiple times.
BlobType
Maps Uint8List values from and to sql
BoolType
A mapper for boolean values in sql. Booleans are represented as integers, where 0 means false and any other value means true.
Column<T>
Base class for columns in sql. Type T refers to the type a value of this column will have in Dart.
ColumnBuilder<T>
A column builder is used to specify which columns should appear in a table. All of the methods defined in this class and its subclasses are not meant to be called at runtime. Instead, the generator will take a look at your source code (specifically, it will analyze which of the methods you use) to figure out the column structure of a table.
Component
A component is anything that can appear in a sql query.
Constant<T>
An expression that represents the value of a dart object encoded to sql by writing them into the sql statements. For most cases, consider using Variable instead.
CustomExpression<D>
A custom expression that can appear in a sql statement. The CustomExpression.content will be written into the query without any modification. [...]
CustomResultSet
Base class for classes generated by custom queries in .drift files.
CustomSelectStatement
A select statement that is constructed with a raw sql prepared statement instead of the high-level drift api.
DatabaseAccessor<T extends GeneratedDatabase>
Class that runs queries to a subset of all available queries in a database. [...]
DatabaseConnection
A database connection managed by drift. Contains three components: [...]
DatabaseConnectionUser
Manages a DatabaseConnection to send queries to the database.
DatabaseSchemaEntity
Some abstract schema entity that can be stored in a database. This includes tables, triggers, views, indexes, etc.
DataClass
A common supertype for all data classes generated by drift. Data classes are immutable structures that represent a single row in a database table.
DataClassName
A class to be used as an annotation on Table classes to customize the name for the data class that will be generated for the table class. The data class is a dart object that will be used to represent a row in the table. [...]
DateTimeType
Maps DateTime values from and to sql
DeleteStatement<T extends Table, D>
A DELETE statement in sql
DoUpdate<T extends Table, D>
A DoUpdate upsert clause can be used to insert or update a custom companion when the underlying companion already exists. [...]
DriftAccessor
Annotation to use on classes that implement DatabaseAccessor. It specifies which tables should be made available in this dao. [...]
DriftDatabase
Use this class as an annotation to inform the generator that a database class should be generated using the specified DriftDatabase.tables. [...]
DriftRuntimeOptions
Defines additional runtime behavior for drift. Changing the fields of this class is rarely necessary.
EnumIndexConverter<T>
Implementation for an enum to int converter that uses the index of the enum as the value stored in the database.
Expression<D>
Any sql expression that evaluates to some generic value. This does not include queries (which might evaluate to multiple values) but individual columns, functions and operators. [...]
FunctionCallExpression<R>
A sql expression that calls a function. [...]
FunctionParameter
Base class for everything that can be used as a function parameter in sql. [...]
GeneratedColumn<T>
Implementation for a Column declared on a table.
GeneratedColumnWithTypeConverter<D, S>
A GeneratedColumn with a type converter attached to it. [...]
GeneratedDatabase
A base class for all generated databases.
GenerationContext
Contains information about a query while it's being constructed.
GroupBy
A "group by" clause in sql.
HasResultSet
Base class for dsl Tables and Views.
Index
A sqlite index on columns or expressions. [...]
Insertable<D>
Common interface for objects which can be inserted or updated into a database. D is the associated data class.
InsertStatement<T extends Table, D>
Represents an insert statement
IntType
Maps int values from and to sql
Join<T extends HasResultSet, D>
Used internally by drift when calling SimpleSelectStatement.join. [...]
JoinedSelectStatement<FirstT extends HasResultSet, FirstD>
A SELECT statement that operates on more than one table.
JsonKey
Annotation to use on column getters inside of a Table to define the name of the column in the json used by DataClass.toJson. [...]
LazyDatabase
A special database executor that delegates work to another QueryExecutor. The other executor is lazily opened by a DatabaseOpener.
Limit
A limit clause inside a select, update or delete statement.
MigrationStrategy
Handles database migrations by delegating work to OnCreate and OnUpgrade methods.
Migrator
Runs migrations declared by a MigrationStrategy.
MultiExecutor
A query executor for drift that delegates work to multiple executors.
MultiSelectable<T>
Selectable methods for returning multiple results. [...]
NullAwareTypeConverter<D, S extends Object>
A type converter automatically mapping null values to null in both directions. [...]
OnCreateQuery
An internal schema entity to run an sql statement when the database is created. [...]
OpeningDetails
Provides information about whether migrations ran before opening the database.
OrderBy
An order-by clause as part of a select statement. The clause can consist of multiple OrderingTerms, with the first terms being more important and the later terms only being considered if the first term considers two rows equal.
OrderingTerm
A single term in a OrderBy clause. The priority of this term is determined by its position in OrderBy.terms.
Precedence
Used to order the precedence of sql expressions so that we can avoid unnecessary parens when generating sql statements.
Query<T extends HasResultSet, D>
Statement that operates with data that already exists (select, delete, update).
QueryExecutor
A query executor is responsible for executing statements on a database and return their results in a raw form. [...]
QueryExecutorUser
Callbacks passed to QueryExecutor.ensureOpen to run schema migrations when the database is first opened.
QueryRow
For custom select statements, represents a row in the result set.
RawValuesInsertable<D>
An Insertable implementation based on raw column expressions. [...]
RealType
Maps double values from and to sql
ResultSetImplementation<Tbl, Row>
Interface for schema entities that have a result set. [...]
Selectable<T>
Abstract class for queries which can return one-time values or a stream of values. [...]
SimpleSelectStatement<T extends HasResultSet, D>
A select statement that doesn't use joins. [...]
SingleOrNullSelectable<T>
Selectable methods for returning or streaming single, nullable results. [...]
SingleSelectable<T>
Selectable methods for returning or streaming single, non-nullable results. [...]
SqlType<T>
A type that can be mapped from Dart to sql. The generic type parameter T denotes the resolved dart type.
SqlTypeSystem
Manages the set of SqlType known to a database. It's also responsible for returning the appropriate sql type for a given dart type.
StreamQueryUpdateRules
Collects a set of UpdateRules which can be used to express how a set of direct updates to a table affects other updates. [...]
StringType
Mapper for string values in sql.
Table
Subclasses represent a table in a database generated by drift.
TableMigration
Contains instructions needed to run a complex migration on a table, using the steps described in Making other kinds of table schema changes. [...]
TableUpdate
Contains information on how a table was updated, which can be used to find queries that are affected by this.
TableUpdateQuery
A table update query describes information to listen for TableUpdates. [...]
TransactionExecutor
A QueryExecutor that runs multiple queries atomically.
Trigger
A sqlite trigger that's executed before, after or instead of a subset of writes on a specific tables. In drift, triggers can only be declared in .drift files. [...]
TypeConverter<D, S>
Maps a custom dart object of type D into a primitive type S understood by the sqlite backend. [...]
TypedResult
A result row in a JoinedSelectStatement that can parse the result of multiple entities.
Uint8List
A fixed-length list of 8-bit unsigned integers. [...]
UpdateCompanion<D>
An update companion for a DataClass which is used to write data into a database using InsertStatement.insert or UpdateStatement.write. [...]
UpdateRule
A common rule that describes how a TableUpdate has other TableUpdates. [...]
UpdateStatement<T extends Table, D>
Represents an UPDATE statement in sql.
UpsertClause<T extends Table, D>
A upsert clause controls how to behave when a uniqueness constraint is violated during an insert. [...]
UpsertMultiple<T extends Table, D>
Upsert clause that consists of multiple clauses. [...]
UseRowClass
An annotation specifying an existing class to be used as a data class.
Value<T>
A wrapper around arbitrary data T to indicate presence or absence explicitly. [...]
ValueSerializer
Serializer responsible for mapping atomic types from and to json.
Variable<T>
An expression that represents the value of a dart object encoded to sql using prepared statements.
VerificationContext
Used internally by drift for integrity checks.
VerificationMeta
Additional information that is passed to GeneratedColumns when verifying data to provide more helpful error messages.
VerificationResult
Returned by GeneratedColumn.isAcceptableValue to provide a description when a valid is invalid.
View<Self, Row>
A sqlite view. [...]
Where
A where clause in a select, update or delete statement.
WritePropagation
An UpdateRule for triggers that exist in a database. [...]

Mixins

LimitContainerMixin<T extends HasResultSet, D>
Mixin to provide the high-level limit methods for users.
SingleTableQueryMixin<T extends HasResultSet, D>
Mixin for a Query that operates on a single primary table only.
TableInfo<TableDsl extends Table, D>
Base class for generated table classes. [...]
VirtualTableInfo<TableDsl extends Table, D>
Additional interface for tables in a drift file that have been created with an CREATE VIRTUAL TABLE STATEMENT.

Extensions

ArithmeticAggregates
Provides aggregate functions that are available for numeric expressions.
ArithmeticExpr
Defines the -, * and / operators on sql expressions that support it.
BaseAggregate
Provides aggregate functions that are available for each expression.
BooleanExpressionOperators
Defines operations on boolean values.
BuildColumn
DSL extension to define a column inside a drift table.
BuildIntColumn
Tells the generator to build an IntColumn. See the docs at ColumnBuilder for details.
BuildTextColumn
Tells the generator to build an TextColumn. See the docs at ColumnBuilder for details.
ComparableExpr
Defines extension functions to express comparisons in sql
DateTimeAggregate
Provides aggregate functions that are available on date time expressions.
DateTimeExpressions
Provides expressions to extract information from date time values, or to calculate the difference between datetimes.
DestructiveMigrationExtension
Extension providing the destructiveFallback strategy.
NameWithAlias
Extension to generate an alias for a table or a view.
OldDbFieldInDatabaseAccessor
Extension for generated dao classes to keep the old db field that was renamed to DatabaseAccessor.attachedDatabase in drift 3.0
QueryTableExtensions
Extension for statements on a table. [...]
RowIdExtension
Extension to use the rowid of a table in Dart queries.
SqlIsNull
Extension defines the isNull and isNotNull members to check whether the expression evaluates to null or not.
StringExpressionOperators
Defines methods that operate on a column storing String values.
TableInfoUtils
Static extension members for generated table classes. [...]

Constants

currentDate → const Expression<DateTime>
A sql expression that evaluates to the current date represented as a unix timestamp. The hour, minute and second fields will be set to 0.
_CustomDateTimeExpression("strftime('%s', CURRENT_DATE)")
currentDateAndTime → const Expression<DateTime>
A sql expression that evaluates to the current date and time, similar to DateTime.now. Timestamps are stored with a second accuracy.
_CustomDateTimeExpression("strftime('%s', CURRENT_TIMESTAMP)")
required → const Required
Used to annotate a named parameter p in a method or function f. Indicates that every invocation of f must include an argument corresponding to p, despite the fact that p would otherwise be an optional parameter. [...]

Properties

driftRuntimeOptions DriftRuntimeOptions
Stores the DriftRuntimeOptions describing global drift behavior across databases. [...]
read / write

Functions

$expandVar(int start, int amount) String
Used by generated code.
coalesce<T>(List<Expression<T?>> expressions) Expression<T>
Evaluates to the first expression in expressions that's not null, or null if all expressions evaluate to null.
countAll({Expression<bool?>? filter}) Expression<int>
Returns the amount of rows in the current group matching the optional filter. [...]
crossJoin<T extends HasResultSet, D>(ResultSetImplementation<T, D> other, {bool? useColumns}) Join<HasResultSet, dynamic>
Creates a sql cross join that can be used in SimpleSelectStatement.join. [...]
existsQuery(BaseSelectStatement select) Expression<bool>
The EXISTS operator checks whether the select subquery returns any rows.
innerJoin<T extends HasResultSet, D>(ResultSetImplementation<T, D> other, Expression<bool?> on, {bool? useColumns}) Join<HasResultSet, dynamic>
Creates a sql inner join that can be used in SimpleSelectStatement.join. [...]
isNotNull(Expression inner) Expression<bool>
Expression that is true if the inner expression resolves to a non-null value.
@Deprecated('Use isNotNull through the SqlIsNull extension')
isNull(Expression inner) Expression<bool>
Expression that is true if the inner expression resolves to a null value.
@Deprecated('Use isNull through the SqlIsNull extension')
leftOuterJoin<T extends HasResultSet, D>(ResultSetImplementation<T, D> other, Expression<bool?> on, {bool? useColumns}) Join<HasResultSet, dynamic>
Creates a sql left outer join that can be used in SimpleSelectStatement.join. [...]
notExistsQuery(BaseSelectStatement select) Expression<bool>
The NOT EXISTS operator evaluates to true if the select subquery does not return any rows.
subqueryExpression<R>(BaseSelectStatement statement) Expression<R>
Creates a subquery expression from the given statement. [...]

Enums

Collate
Builtin collating functions from sqlite. [...]
InsertMode
Enumeration of different insert behaviors. See the documentation on the individual fields for details.
OrderingMode
Describes how to order rows
SqlDialect
An enumeration of database systems supported by drift. Only SqlDialect.sqlite is officially supported, all others are in an experimental state at the moment.
UpdateKind
Classifies a TableUpdate by what kind of write happened - an insert, an update or a delete operation.

Typedefs

BlobColumn = Column<Uint8List?>
A column that stores arbitrary blobs of data as a Uint8List.
BoolColumn = Column<bool?>
A column that stores boolean values. Booleans will be stored as an integer that can either be 0 (false) or 1 (true).
DatabaseOpener = FutureOr<QueryExecutor> Function()
Signature of a function that opens a database connection when instructed to.
DateTimeColumn = Column<DateTime?>
A column that stores a DateTime. Times will be stored as unix timestamp and will thus have a second accuracy.
IntColumn = Column<int?>
A column that stores int values.
OnBeforeOpen = Future<void> Function(OpeningDetails details)
Signature of a function that's called before a database is marked opened by drift, but after migrations took place. This is a suitable callback to to populate initial data or issue PRAGMA statements that you want to use.
OnCreate = Future<void> Function(Migrator m)
Signature of a function that will be invoked when a database is created.
OnUpgrade = Future<void> Function(Migrator m, int from, int to)
Signature of a function that will be invoked when a database is upgraded or downgraded. In version upgrades: from < to In version downgrades: from > to
OrderClauseGenerator<T> = OrderingTerm Function(T tbl)
Signature of a function that generates an OrderingTerm when provided with a table.
RealColumn = Column<double?>
A column that stores floating point numeric values.
TextColumn = Column<String?>
A column that stores text.

Exceptions / Errors

CouldNotRollBackException
Exception thrown by drift when rolling back a transaction fails. [...]
DriftWrappedException
A wrapper class for internal exceptions thrown by the underlying database engine when drift can give additional context or help. [...]
InvalidDataException
Thrown when one attempts to insert or update invalid data into a table.