SQL::Statement::Function - abstract base class for all function executing terms
# this class doesn't have a common constructor, because all derived classes # have their special requirements
SQL::Statement::Function is an abstract base class providing the interface for all function executing terms.
SQL::Statement::Function ISA SQL::Statement::Term
Destroys the term and undefines the weak reference to the owner as well as the reference to the parameter list.
SQL::Statement::Function::UserFunc - implements executing a perl subroutine
# create an user function term with an SQL::Statement object as owner, # specifying the function name, the subroutine name (full qualified) # and the parameters to the subroutine my $term = SQL::Statement::Function::UserFunc->new( $owner, $name, $sub, \@params ); # access the result of that operation $term->value( $eval );
SQL::Statement::Function::UserFunc implements a term which returns the result of the specified subroutine.
Instantiates a new SQL::Statement::Function::UserFunc instance.
SQL::Statement::Function::UserFunc
Invokes the given subroutine with the values of the params and return it's result:
my @params = map { $_->value($eval); } @{ $self->{PARAMS} }; return $subpkg->$subname( $self->{OWNER}, @params );
SQL::Statement::Function::NumericEval - implements numeric evaluation of a term
# create an user function term with an SQL::Statement object as owner, # specifying the expression to evaluate and the parameters to the subroutine my $term = SQL::Statement::NumericEval->new( $owner, $expr, \@params ); # access the result of that operation $term->value( $eval );
SQL::Statement::Function::NumericEval implements the numeric evaluation of a term. All parameters are expected to be numeric.
SQL::Statement::Function::NumericEval ISA SQL::Statement::Function ISA SQL::Statement::Term
Instantiates a new SQL::Statement::Function::NumericEval instance. Takes $owner, $expr and \@params as arguments (in specified order).
SQL::Statement::Function::NumericEval
Returns the result of the evaluated expression.
SQL::Statement::Function::Trim - implements the built-in trim function support
# create an trim function term with an SQL::Statement object as owner, # specifying the spec, char and the parameters to the subroutine my $term = SQL::Statement::Trim->new( $owner, $spec, $char, \@params ); # access the result of that operation $term->value( $eval );
SQL::Statement::Function::Trim implements string trimming.
SQL::Statement::Function::Trim ISA SQL::Statement::Function ISA SQL::Statement::Term
Instantiates a new SQL::Statement::Function::Trim instance. Takes $owner, $spec, $char and \@params as arguments (in specified order).
SQL::Statement::Function::Trim
Meaning of the parameters:
Can be on of 'LEADING', 'TRAILING' 'BOTH'. Trims the leading chars, trailing chars or at both ends, respectively.
Defaults to 'BOTH'.
The character to trim - defaults to ' '
' '
Expected to be an array with exact 1 element (more aren't evaluated).
Returns the trimmed value of first parameter argument.
SQL::Statement::Function::SubString - implements the built-in sub-string function support
# create an substr function term with an SQL::Statement object as owner, # specifying the start and length of the sub string to extract from the # first element of \@params my $term = SQL::Statement::SubString->new( $owner, $start, $length, \@params ); # access the result of that operation $term->value( $eval );
SQL::Statement::Function::SubString implements a sub-string extraction term.
SQL::Statement::Function::SubString ISA SQL::Statement::Function ISA SQL::Statement::Term
Instantiates a new SQL::Statement::Function::SubString instance. Takes $owner, $start, $length and \@params as arguments (in specified order).
SQL::Statement::Function::SubString
Specifies the start position to extract the sub-string. This is expected to be a SQL::Statement::Term instance. The first character in a string has the position 1.
Specifies the length of the extracted sub-string. This is expected to be a SQL::Statement::Term instance.
If omitted, everything to the end of the string is returned.
Returns the extracted sub-string value from first parameter argument.
SQL::Statement::Function::StrConcat - implements the built-in string concatenation
# create an substr function term with an SQL::Statement object as owner # and \@params to concatenate my $term = SQL::Statement::StrConcat->new( $owner, \@params ); # access the result of that operation $term->value( $eval );
SQL::Statement::Function::StrConcat implements a string concatenation term.
SQL::Statement::Function::StrConcat ISA SQL::Statement::Function ISA SQL::Statement::Term
Instantiates a new SQL::Statement::Function::StrConcat instance.
SQL::Statement::Function::StrConcat
Returns the concatenated string composed of the parameter values.
Copyright (c) 2009,2010 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.
To install SQL::Statement, copy and paste the appropriate command in to your terminal.
cpanm
cpanm SQL::Statement
CPAN shell
perl -MCPAN -e shell install SQL::Statement
For more information on module installation, please visit the detailed CPAN module installation guide.