org.hibernate.dialect.function
Interface SQLFunction

All Known Implementing Classes:

AnsiTrimEmulationFunction, CastFunction, CharIndexFunction, ClassicAvgFunction, ClassicCountFunction, ClassicSumFunction, ConditionalParenthesisFunction, ConvertFunction, DerbyDialect.DerbyTrimFunctionEmulation, NoArgSQLFunction, NvlFunction, PositionSubstringFunction, SQLFunctionTemplate, StandardJDBCEscapeFunction, StandardSQLFunction, VarArgsSQLFunction

public interface SQLFunction

Provides support routines for the HQL functions as used in the various SQL Dialects Provides an interface for supporting various HQL functions that are translated to SQL. The Dialect and its sub-classes use this interface to provide details required for processing of the function.

Author:

David Channon

Method Summary

Type	getReturnType(Type columnType, Mapping mapping) The return type of the function.
boolean	hasArguments() Does this function have any arguments?
boolean	hasParenthesesIfNoArguments() If there are no arguments, are parens required?
String	render(List args, SessionFactoryImplementor factory) Render the function call as SQL fragment.

Method Detail

getReturnType

Type getReturnType(Type columnType,
                   Mapping mapping)
                   throws QueryException

The return type of the function. May be either a concrete type which is preset, or variable depending upon the type of the first function argument.

Parameters:

columnType - the type of the first argument

mapping - The mapping source.

Returns:

The type to be expected as a return.

Throws:

QueryException - Indicates an issue resolving the return type.

hasArguments

boolean hasArguments()

Does this function have any arguments?

Returns:

True if the function expects to have parameters; false otherwise.

hasParenthesesIfNoArguments

boolean hasParenthesesIfNoArguments()

If there are no arguments, are parens required?

Returns:

True if a no-arg call of this function requires parentheses.

render

String render(List args,
              SessionFactoryImplementor factory)
              throws QueryException

Render the function call as SQL fragment.

Parameters:

args - The function arguments

factory - The SessionFactory

Returns:

The rendered function call

Throws:

QueryException - Indicates a problem rendering the function call.