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.