Package dev.morphia.aggregation.expressions

Class ConditionalExpressions

java.lang.Object

dev.morphia.aggregation.expressions.ConditionalExpressions

public class ConditionalExpressions
extends Object

Defines helper methods for the conditional expressions

Since:

2.0

Method Summary

Modifier and Type	Method	Description
static dev.morphia.aggregation.expressions.impls.Expression	condition(dev.morphia.aggregation.expressions.impls.Expression condition, dev.morphia.aggregation.expressions.impls.Expression then, dev.morphia.aggregation.expressions.impls.Expression otherwise)	Evaluates a boolean expression to return one of the two specified return expressions.
static dev.morphia.aggregation.expressions.impls.IfNull	ifNull()	Evaluates an expression and returns the value of the expression if the expression evaluates to a non-null value.
static dev.morphia.aggregation.expressions.impls.SwitchExpression	switchExpression()	Evaluates a series of case expressions.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

condition

public static dev.morphia.aggregation.expressions.impls.Expression condition(dev.morphia.aggregation.expressions.impls.Expression condition,
                                                                             dev.morphia.aggregation.expressions.impls.Expression then,
                                                                             dev.morphia.aggregation.expressions.impls.Expression otherwise)

Evaluates a boolean expression to return one of the two specified return expressions.

Parameters:

condition - the condition to evaluate

then - the expression for the true branch

otherwise - the expresion for the else branch

Returns:

the new expression

MongoDB documentation

Aggregration Expression: $cond

ifNull

public static dev.morphia.aggregation.expressions.impls.IfNull ifNull()

Evaluates an expression and returns the value of the expression if the expression evaluates to a non-null value. If the expression evaluates to a null value, including instances of undefined values or missing fields, returns the value of the replacement expression.

Returns:

the new expression

MongoDB documentation

Aggregration Expression: $ifNull

switchExpression

public static dev.morphia.aggregation.expressions.impls.SwitchExpression switchExpression()

Evaluates a series of case expressions. When it finds an expression which evaluates to true, $switch executes a specified expression and breaks out of the control flow.

Returns:

the new expression

MongoDB documentation

Aggregration Expression: $switch