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 Expression	condition(Object condition, Object then, Object otherwise)	Evaluates a boolean expression to return one of the two specified return expressions.
static IfNull	ifNull()	Evaluates an expression and returns the value of the expression if the expression evaluates to a non-null value.
static 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 Details

condition

public static Expression condition(Object condition,
 Object then,
 Object 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 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

Since server release

5.0

MongoDB documentation

Aggregration Expression: $ifNull

switchExpression

public static 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