A predicate contains instructions for filtering rows when performing a Query.

Predicates currently are the WHERE clause in a SQL statement and are used verbatim by the PersistentStore. In general, you should use Query.where instead of using this class directly, as Query.where will use the underlying PersistentStore to generate a QueryPredicate for you.

A predicate has a format and parameters. The format is the String that comes after WHERE in a SQL query. The format may have parameterized values, for which the corresponding value is in the parameters map. A parameter is prefixed with '@' in the format string. Currently, the format string's parameter syntax is defined by the PersistentStore it is used on. An example of that format:

var predicate = new QueryPredicate("x = @xValue", {"xValue" : 5});

Static Methods

andPredicates(Iterable<QueryPredicate> predicates) QueryPredicate

Joins together a list of predicates by the 'and' token.

Constructors

QueryPredicate(String format, Map<String, dynamic> parameters)

Default constructor

Properties

format → String

The string format of the this predicate.

read / write
parameters → Map<String, dynamic>

A map of values to replace in the format string at execution time.

read / write
hashCode → int

The hash code for this object.

read-only, inherited
runtimeType → Type

A representation of the runtime type of the object.

read-only, inherited

Operators

operator ==(other) → bool

The equality operator.

inherited

Methods

noSuchMethod(Invocation invocation) → dynamic

Invoked when a non-existent method or property is accessed.

inherited
toString() → String

Returns a string representation of this object.

inherited