com.blazebit.persistence.spi

Interface JpqlFunction

public interface JpqlFunction

Interface for implementing a JPA custom function that renders dbms specific code. An instance of this interface needs to be registered to be able to use the function in queries.

Since:

1.0

Author:

Christian Beikov

See Also:

EntityManagerIntegrator.registerFunctions(javax.persistence.EntityManager, java.util.Map)

Method Summary

Methods

Modifier and Type	Method and Description
Class<?>	getReturnType(Class<?> firstArgumentType) Returns the return type of this function.
boolean	hasArguments() Returns true if the function has arguments, false otherwise.
boolean	hasParenthesesIfNoArguments() Returns false if parentheses might be skipped if no arguments are given, true otherwise.
void	render(FunctionRenderContext context) Renders the function into the given function render context

Method Detail

hasArguments

boolean hasArguments()

Returns true if the function has arguments, false otherwise.

Returns:

true if the function has arguments, false otherwise

hasParenthesesIfNoArguments

boolean hasParenthesesIfNoArguments()

Returns false if parentheses might be skipped if no arguments are given, true otherwise.

Returns:

false if parentheses might be skipped if no arguments are given, true otherwise

getReturnType

Class<?> getReturnType(Class<?> firstArgumentType)

Returns the return type of this function. The return type may be null, but beware that nesting this function into other expressions may then fail.

Parameters:

firstArgumentType - The type of the first argument

Returns:

the return type of this function, or null

render

void render(FunctionRenderContext context)

Renders the function into the given function render context

Parameters:

context - The context into which the function should be rendered