程序包 org.hibernate.dialect.function

接口 SQLFunction

所有已知实现类:

AbstractAnsiTrimEmulationFunction, AnsiTrimEmulationFunction, AnsiTrimFunction, AvgWithArgumentCastFunction, CastFunction, CharIndexFunction, ConditionalParenthesisFunction, ConvertFunction, DB2SubstringFunction, DerbyConcatFunction, NoArgSQLFunction, NvlFunction, PositionSubstringFunction, SQLFunctionTemplate, StandardAnsiSqlAggregationFunctions.AvgFunction, StandardAnsiSqlAggregationFunctions.CountFunction, StandardAnsiSqlAggregationFunctions.MaxFunction, StandardAnsiSqlAggregationFunctions.MinFunction, StandardAnsiSqlAggregationFunctions.SumFunction, StandardJDBCEscapeFunction, StandardSQLFunction, StaticPrecisionFspTimestampFunction, TrimFunctionTemplate, 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.

作者:

David Channon, Steve Ebersole

方法概要

修饰符和类型	方法	说明
Type	getReturnType(Type firstArgumentType, Mapping mapping)	The return type of the function.
boolean	hasArguments()	Does this function have any arguments?
boolean	hasParenthesesIfNoArguments()	If there are no arguments, are parentheses required?
String	render(Type firstArgumentType, List arguments, SessionFactoryImplementor factory)	Render the function call as SQL fragment.

方法详细资料

hasArguments

boolean hasArguments()

Does this function have any arguments?

返回:

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

hasParenthesesIfNoArguments

boolean hasParenthesesIfNoArguments()

If there are no arguments, are parentheses required?

返回:

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

getReturnType

Type getReturnType(Type firstArgumentType,
                   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.

Note, the 'firstArgumentType' parameter should match the one passed into render(org.hibernate.type.Type, java.util.List, org.hibernate.engine.spi.SessionFactoryImplementor)

参数:

firstArgumentType - The type of the first argument

mapping - The mapping source.

返回:

The type to be expected as a return.

抛出:

QueryException - Indicates an issue resolving the return type.

render

String render(Type firstArgumentType,
              List arguments,
              SessionFactoryImplementor factory)
       throws QueryException

Render the function call as SQL fragment.

Note, the 'firstArgumentType' parameter should match the one passed into getReturnType(org.hibernate.type.Type, org.hibernate.engine.spi.Mapping)

参数:

firstArgumentType - The type of the first argument

arguments - The function arguments

factory - The SessionFactory

返回:

The rendered function call

抛出:

QueryException - Indicates a problem rendering the function call.