SQL::Pygmy - SQL text kept together with bind values

version 0.01

use SQL::Pygmy;

my $sp = SQL::Pygmy->new;

SQL::Pygmy methods returns and manipulate with SQL pieces. SQL piece is nothing more than text (containing positional placeholders ?) plus the array of positional parameters.

Except of object returned by SQL::Pygmy method, SQL piece can be:

• defined scalar value. It is a piece of SQL having text only and no parameters.
• an array with one or two elements. It stands for placeholder only ? and single value (and possibly its $bind_type or $bind_attr (see bind_param in DBI).

• new

  Constructor. So far parameterless.

• text($arg)

  Extracts text part of the argument

• bindings($arg)

  Extract the bindings as an array reference for whatever can be a SQL piece.

• concat(@args)

  Concatenates all SQL pieces together, i.e. join their texts by empty string and merges their bindings.

• join($sep, @args)

  Concatenates all SQL pieces together, i.e. join their texts by $sep string and merges their bindings.

• as_value($arg)

  Converts the $arg to a SQL piece as value, i.e. object returned by SQL::Pygmy methods is left as is, other value is connverted to single placeholder text '?' and bind value (the $arg).

• values(@args)

  Converts every arg to SQL piece as value (see above), joins the pieces by , (comma) and wraps the result into parenthesis. Throws an exception if the @args is empty.

• true

  Returns SQL piece which can stand true in WHERE conditions. Basically 1=1.

• false

  Returns SQL piece which can stand false in WHERE conditions. Basically 1=0.

• and(@args)

  Returns:

  • $sp->true for empty @args
  • the only element from @args, if @args contains just one element
  • concatenation of the elements from @args, where each element is put into parenthesis and the elements are joined by ' AND '

• or(@args)

  • $sp->false for empty @args
  • the only element from @args, if @args contains just one element
  • concatenation of the elements from @args, where each element is put into parenthesis and the elements are joined by ' OR '

• apply($dbh, $arg)

  Prepares and executes the command on database handler, returns the statement handle. Roughly equivalent to:

    my $sth = $dbh->prepare($sp->text($arg));
    $sth->execute(@{$sp->bindings($arg)}); 
    return $sth;
  

Roman Daniel [email protected]

This software is copyright (c) 2022 by Roman Daniel.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.