Expression<D> class Null safety

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.

It's important that all subclasses properly implement hashCode and ==.

Implemented types
Available Extensions


Constant constructor so that subclasses can be constant.


hashCode int
The hash code for this object. [...]
read-only, inherited
isLiteral bool
Whether this expression is a literal. Some use-sites need to put parentheses around non-literals.
precedence Precedence
The precedence of this expression. This can be used to automatically put parentheses around expressions as needed.
runtimeType Type
A representation of the runtime type of the object.
read-only, inherited


caseMatch<T>({required Map<Expression<D>, Expression<T?>> when, Expression<T?>? orElse}) Expression<T?>
A CASE WHEN construct using the current expression as a base. [...]
cast<D2>() Expression<D2>
Generates a CAST(expression AS TYPE) expression. [...]
dartCast<D2>() Expression<D2>
Casts this expression to an expression of D. [...]
equals(D compare) Expression<bool>
Whether this column is equal to the given value, which must have a fitting type. The compare value will be written as a variable using prepared statements, so there is no risk of an SQL-injection.
equalsExp(Expression<D> compare) Expression<bool>
Whether this expression is equal to the given expression.
findType(SqlTypeSystem types) SqlType<D>
Finds the runtime implementation of D in the provided types.
isIn(Iterable<D> values) Expression<bool?>
An expression that is true if this resolves to any of the values in values.
isInQuery(BaseSelectStatement select) Expression<bool?>
An expression checking whether this is included in any row of the provided select statement. [...]
isNotIn(Iterable<D> values) Expression<bool?>
An expression that is true if this does not resolve to any of the values in values.
isNotInQuery(BaseSelectStatement select) Expression<bool?>
An expression checking whether this is not included in any row of the provided select statement. [...]
noSuchMethod(Invocation invocation) → dynamic
Invoked when a non-existent method or property is accessed. [...]
toString() String
A string representation of this object. [...]
writeAroundPrecedence(GenerationContext context, Precedence precedence) → void
Writes this expression into the GenerationContext, assuming that there's an outer expression with precedence. If the Expression.precedence of this expression is lower, it will be wrap}ped in [...]
writeInner(GenerationContext ctx, Expression inner) → void
If this Expression wraps an inner expression, this utility method can be used inside writeInto to write that inner expression while wrapping it in parentheses if necessary.
writeInto(GenerationContext context) → void
Writes this component into the context by writing to its GenerationContext.buffer or by introducing bound variables. When writing into the buffer, no whitespace around the this component should be introduced. When a component consists of multiple composed component, it's responsible for introducing whitespace between its child components.


operator ==(Object other) bool
The equality operator. [...]