NAME

SQL::Abstract::Tree - Represent SQL as an AST

SYNOPSIS

my $sqla_tree = SQL::Abstract::Tree->new({ profile => 'console' });

print $sqla_tree->format('SELECT * FROM foo WHERE foo.a > 2');

# SELECT *
#   FROM foo
#   WHERE foo.a > 2

METHODS

new

my $sqla_tree = SQL::Abstract::Tree->new({ profile => 'console' });

$args = {
  profile => 'console',      # predefined profile to use (default: 'none')
  fill_in_placeholders => 1, # true for placeholder population
  placeholder_surround =>    # The strings that will be wrapped around
             [GREEN, RESET], # populated placeholders if the above is set
  indent_string => ' ',      # the string used when indenting
  indent_amount => 2,        # how many of above string to use for a single
                             # indent level
  newline       => "\n",     # string for newline
  html_escape   => 0,        # HTML-escape the SQL text and the filled in
                             # placeholders (but not the strings above)
  colormap      => {
    select => [RED, RESET], # a pair of strings defining what to surround
                            # the keyword with for colorization
    # ...
  },
  indentmap     => {
    select        => 0,     # A zero means that the keyword will start on
                            # a new line
    from          => 1,     # Any other positive integer means that after
    on            => 2,     # said newline it will get that many indents
    # ...
    and           => 1,     # optional, see "Lines of their own" below
    or            => 1,
    ','           => 1,
  },
}

Returns a new SQL::Abstract::Tree object. All arguments are optional.

Lines of their own

Besides clause keywords, the indentmap understands three more entries, none of which is set by the predefined profiles:

and, or

Every further condition joined with AND (or OR) starts a new line, indented by that many levels below its clause (or below the parenthesis it is in).

,

The items of a comma list right below a clause (the select list, ORDER BY, GROUP BY, SET ...) each get a line of their own, indented by that many levels below the clause. Lists further down, like function arguments or an IN list, stay on one line.

Merge them into a profile like any other override:

my $sqlat = SQL::Abstract::Tree->new({
  profile   => 'console',
  indentmap => { and => 1, or => 1, ',' => 1 },
});

print $sqlat->format(
  'SELECT a, b FROM t WHERE x = ? AND y = ? ORDER BY a, b', [1, 2]
);

# SELECT
#   a,
#   b
#   FROM t
# WHERE x = 1
#   AND y = 2
# ORDER BY
#   a,
#   b

They only have an effect when a "newline" is set.

profiles

There are four predefined profiles, none, console, console_monochrome, and html. Typically a user will probably just use console or console_monochrome, but if something about a profile bothers you, merely use the profile and override the parts that you don't like.

The html profile sets "html_escape", so its output can go straight into an HTML page: bind values and SQL text are escaped, the profile's own <span> and <br /> markup is not.

format

$sqlat->format('SELECT * FROM bar WHERE x = ?', [1])

Takes $sql and \@bindargs.

Returns a formatting string based on the string passed in

parse

$sqlat->parse('SELECT * FROM bar WHERE x = ?')

Returns a "tree" representing passed in SQL. Please do not depend on the structure of the returned tree. It may be stable at some point, but not yet.

unparse

$sqlat->unparse($tree_structure, \@bindargs)

Transform "tree" into SQL, applying various transforms on the way.

format_keyword

$sqlat->format_keyword('SELECT')

Currently this just takes a keyword and puts the colormap stuff around it. Later on it may do more and allow for coderef based transforms.

pad_keyword

my ($before, $after) = @{$sqlat->pad_keyword('SELECT')};

Returns whitespace to be inserted around a keyword.

fill_in_placeholder

my $value = $sqlat->fill_in_placeholder(\@bindargs)

Removes last arg from passed arrayref and returns it, surrounded with the values in placeholder_surround, and then surrounded with single quotes.

indent

Returns as many indent strings as indent amounts times the first argument.

ACCESSORS

colormap

See "new"

fill_in_placeholders

See "new"

html_escape

See "new" and "profiles"

indent_amount

See "new"

indent_string

See "new"

indentmap

See "new"

newline

See "new"

placeholder_surround

See "new"

cpanm SQL::Abstract

perl -MCPAN -e shell
install SQL::Abstract