org.hibernate.dialect.function
Class AbstractAnsiTrimEmulationFunction

java.lang.Object
  extended by org.hibernate.dialect.function.AbstractAnsiTrimEmulationFunction
All Implemented Interfaces:
SQLFunction
Direct Known Subclasses:
AnsiTrimEmulationFunction

public abstract class AbstractAnsiTrimEmulationFunction
extends Object
implements SQLFunction

A SQLFunction providing support for implementing TRIM functionality (as defined by both the ANSI SQL and JPA specs) in cases where the dialect may not support the full trim function itself.

Follows the template pattern in order to implement the render(org.hibernate.type.Type, java.util.List, org.hibernate.engine.SessionFactoryImplementor) method.

Author:
Steve Ebersole

Constructor Summary
AbstractAnsiTrimEmulationFunction()
           
 
Method Summary
 Type getReturnType(Type argumentType, 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 argumentType, List args, SessionFactoryImplementor factory)
          Render the function call as SQL fragment.
protected abstract  SQLFunction resolveBothSpaceTrimFromFunction()
          Resolve the function definition which should be used to trim both leading and trailing spaces.
protected abstract  SQLFunction resolveBothSpaceTrimFunction()
          Resolve the function definition which should be used to trim both leading and trailing spaces.
protected abstract  SQLFunction resolveBothTrimFunction()
          Resolve the function definition which should be used to trim the specified character from both the beginning (leading) and end (trailing) of the trim source.
protected abstract  SQLFunction resolveLeadingSpaceTrimFunction()
          Resolve the function definition which should be used to trim leading spaces.
protected abstract  SQLFunction resolveLeadingTrimFunction()
          Resolve the function definition which should be used to trim the specified character from the beginning (leading) of the trim source.
protected abstract  SQLFunction resolveTrailingSpaceTrimFunction()
          Resolve the function definition which should be used to trim trailing spaces.
protected abstract  SQLFunction resolveTrailingTrimFunction()
          Resolve the function definition which should be used to trim the specified character from the end (trailing) of the trim source.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

AbstractAnsiTrimEmulationFunction

public AbstractAnsiTrimEmulationFunction()
Method Detail

hasArguments

public final boolean hasArguments()
Does this function have any arguments?

Specified by:
hasArguments in interface SQLFunction
Returns:
True if the function expects to have parameters; false otherwise.

hasParenthesesIfNoArguments

public final boolean hasParenthesesIfNoArguments()
If there are no arguments, are parentheses required?

Specified by:
hasParenthesesIfNoArguments in interface SQLFunction
Returns:
True if a no-arg call of this function requires parentheses.

getReturnType

public final Type getReturnType(Type argumentType,
                                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 SQLFunction.render(org.hibernate.type.Type, java.util.List, org.hibernate.engine.SessionFactoryImplementor)

Specified by:
getReturnType in interface SQLFunction
Parameters:
argumentType - 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.

render

public final String render(Type argumentType,
                           List args,
                           SessionFactoryImplementor factory)
                    throws QueryException
Render the function call as SQL fragment.

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

Specified by:
render in interface SQLFunction
Parameters:
argumentType - The type of the first argument
args - The function arguments
factory - The SessionFactory
Returns:
The rendered function call
Throws:
QueryException - Indicates a problem rendering the function call.

resolveBothSpaceTrimFunction

protected abstract SQLFunction resolveBothSpaceTrimFunction()
Resolve the function definition which should be used to trim both leading and trailing spaces.

In this form, the imput arguments is missing the FROM keyword.

Returns:
The sql function

resolveBothSpaceTrimFromFunction

protected abstract SQLFunction resolveBothSpaceTrimFromFunction()
Resolve the function definition which should be used to trim both leading and trailing spaces.

The same as {#link resolveBothSpaceTrimFunction} except that here theFROM is included and will need to be accounted for during SQLFunction.render(org.hibernate.type.Type, java.util.List, org.hibernate.engine.SessionFactoryImplementor) processing.

Returns:
The sql function

resolveLeadingSpaceTrimFunction

protected abstract SQLFunction resolveLeadingSpaceTrimFunction()
Resolve the function definition which should be used to trim leading spaces.

Returns:
The sql function

resolveTrailingSpaceTrimFunction

protected abstract SQLFunction resolveTrailingSpaceTrimFunction()
Resolve the function definition which should be used to trim trailing spaces.

Returns:
The sql function

resolveBothTrimFunction

protected abstract SQLFunction resolveBothTrimFunction()
Resolve the function definition which should be used to trim the specified character from both the beginning (leading) and end (trailing) of the trim source.

Returns:
The sql function

resolveLeadingTrimFunction

protected abstract SQLFunction resolveLeadingTrimFunction()
Resolve the function definition which should be used to trim the specified character from the beginning (leading) of the trim source.

Returns:
The sql function

resolveTrailingTrimFunction

protected abstract SQLFunction resolveTrailingTrimFunction()
Resolve the function definition which should be used to trim the specified character from the end (trailing) of the trim source.

Returns:
The sql function


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