# SQL::Statement::Term - phpMan

## NAME
    [SQL::Statement::Term] - base class for all terms

## SYNOPSIS
      # create a term with an [SQL::Statement] object as owner
      my $term = [SQL::Statement::Term]->new( $owner );
      # access the value of that term
      $term->value( $eval );

## DESCRIPTION
    [SQL::Statement::Term] is an abstract base class providing the interface
    for all terms.

## INHERITANCE
      [SQL::Statement::Term]

## METHODS
  new
    Instantiates new term and stores a weak reference to the owner.

  value
    *Abstract* method which will return the value of the term. Must be
    overridden by derived classes.

  DESTROY
    Destroys the term and undefines the weak reference to the owner.

## NAME
    [SQL::Statement::ConstantTerm] - term for constant values

## SYNOPSIS
      # create a term with an [SQL::Statement] object as owner
      my $term = [SQL::Statement::ConstantTerm]->new( $owner, 'foo' );
      # access the value of that term - returns 'foo'
      $term->value( $eval );

## DESCRIPTION
    [SQL::Statement::ConstantTerm] implements a term which will always return
    the same constant value.

## INHERITANCE
      [SQL::Statement::ConstantTerm]
      ISA [SQL::Statement::Term]

## METHODS
  new
    Instantiates new term and stores the constant to deliver and a weak
    reference to the owner.

  value
    Returns the specified constant.

## NAME
    [SQL::Statement::ColumnValue] - term for column values

## SYNOPSIS
      # create a term with an [SQL::Statement] object as owner
      my $term = [SQL::Statement::ColumnValue]->new( $owner, 'id' );
      # access the value of that term - returns the value of the column 'id'
      # of the currently active row in $eval
      $term->value( $eval );

## DESCRIPTION
    [SQL::Statement::ColumnValue] implements a term which will return the
    specified column of the active row.

## INHERITANCE
      [SQL::Statement::ColumnValue]
      ISA [SQL::Statement::Term]

## METHODS
  new
    Instantiates new term and stores the column name to deliver and a weak
    reference to the owner.

  value
    Returns the specified column value.

## AUTHOR AND COPYRIGHT
    Copyright (c) 2009-2020 by Jens Rehsack: rehsackATcpan.org

    All rights reserved.

    You may distribute this module under the terms of either the GNU General
    Public License or the Artistic License, as specified in the Perl README
    file.