X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FSQL%2FAbstract%2FTree.pm;h=ae93c953550bf222e957f66f0c3259e231ec91cc;hb=4247c384fc4291dab9ad93625b267e862b2c9906;hp=dedd8f394812d46c8f618c3b00dc7dc29552b602;hpb=73835ff043d4a737e0e5577c98c88a8fd720bb64;p=dbsrgits%2FSQL-Abstract.git diff --git a/lib/SQL/Abstract/Tree.pm b/lib/SQL/Abstract/Tree.pm index dedd8f3..ae93c95 100644 --- a/lib/SQL/Abstract/Tree.pm +++ b/lib/SQL/Abstract/Tree.pm @@ -68,6 +68,7 @@ my @expression_start_keywords = ( 'HAVING', 'ORDER \s+ BY', 'SKIP', + 'FETCH', 'FIRST', 'LIMIT', 'OFFSET', @@ -82,7 +83,6 @@ my @expression_start_keywords = ( 'SAVEPOINT', 'RELEASE \s+ SAVEPOINT', 'RETURNING', - 'ROW_NUMBER \s* \( \s* \) \s+ OVER', ); my $expr_start_re = join ("\n\t|\n", @expression_start_keywords ); @@ -91,30 +91,32 @@ $expr_start_re = qr/ $op_look_behind (?i: $expr_start_re ) $op_look_ahead /x; # These are binary operator keywords always a single LHS and RHS # * AND/OR are handled separately as they are N-ary # * so is NOT as being unary -# * BETWEEN without paranthesis around the ANDed arguments (which -# makes it a non-binary op) is detected and accomodated in +# * BETWEEN without parentheses around the ANDed arguments (which +# makes it a non-binary op) is detected and accommodated in # _recurse_parse() # * AS is not really an operator but is handled here as it's also LHS/RHS # this will be included in the $binary_op_re, the distinction is interesting during -# testing as one is tighter than the other, plus mathops have different look -# ahead/behind (e.g. "x"="y" ) -my @math_op_keywords = (qw/ - + < > != <> = <= >= /); -my $math_op_re = join ("\n\t|\n", map +# testing as one is tighter than the other, plus alphanum cmp ops have different +# look ahead/behind (e.g. "x"="y" ) +my @alphanum_cmp_op_keywords = (qw/< > != <> = <= >= /); +my $alphanum_cmp_op_re = join ("\n\t|\n", map { "(?: (?<= [\\w\\s] | $quote_right ) | \\A )" . quotemeta ($_) . "(?: (?= [\\w\\s] | $quote_left ) | \\z )" } - @math_op_keywords + @alphanum_cmp_op_keywords ); -$math_op_re = qr/$math_op_re/x; +$alphanum_cmp_op_re = qr/$alphanum_cmp_op_re/x; my $binary_op_re = '(?: NOT \s+)? (?:' . join ('|', qw/IN BETWEEN R?LIKE/) . ')'; $binary_op_re = join "\n\t|\n", "$op_look_behind (?i: $binary_op_re | AS ) $op_look_ahead", - $math_op_re, + $alphanum_cmp_op_re, $op_look_behind . 'IS (?:\s+ NOT)?' . "(?= \\s+ NULL \\b | $op_look_ahead )", ; $binary_op_re = qr/$binary_op_re/x; -my $unary_op_re = '(?: NOT \s+ EXISTS | NOT )'; +my $rno_re = qr/ROW_NUMBER \s* \( \s* \) \s+ OVER/ix; + +my $unary_op_re = 'NOT \s+ EXISTS | NOT | ' . $rno_re; $unary_op_re = join "\n\t|\n", "$op_look_behind (?i: $unary_op_re ) $op_look_ahead", ; @@ -129,14 +131,14 @@ my $tokenizer_re = join("\n\t|\n", $unary_op_re, $asc_desc_re, $and_or_re, - "$op_look_behind \\* $op_look_ahead", + $op_look_behind . ' \* ' . $op_look_ahead, (map { quotemeta $_ } qw/, ( )/), $placeholder_re, ); # this one *is* capturing for the split below # splits on whitespace if all else fails -# has to happen before the composiign qr's are anchored (below) +# has to happen before the composing qr's are anchored (below) $tokenizer_re = qr/ \s* ( $tokenizer_re ) \s* | \s+ /x; # Parser states for _recurse_parse() @@ -149,8 +151,7 @@ use constant PARSE_LIST_ELT => 5; my $expr_term_re = qr/$expr_start_re | \)/x; my $rhs_term_re = qr/ $expr_term_re | $binary_op_re | $unary_op_re | $asc_desc_re | $and_or_re | \, /x; -my $common_single_args_re = qr/ \* | $placeholder_re /x; -my $all_std_keywords_re = qr/ $rhs_term_re | \( | $common_single_args_re /x; +my $all_std_keywords_re = qr/ $rhs_term_re | \( | $placeholder_re /x; # anchor everything - even though keywords are separated by the tokenizer, leakage may occur for ( @@ -158,20 +159,20 @@ for ( $quote_right, $placeholder_re, $expr_start_re, - $math_op_re, + $alphanum_cmp_op_re, $binary_op_re, $unary_op_re, $asc_desc_re, $and_or_re, $expr_term_re, $rhs_term_re, - $common_single_args_re, $all_std_keywords_re, ) { $_ = qr/ \A $_ \z /x; } - +# what can be bunched together under one MISC in an AST +my $compressable_node_re = qr/^ \- (?: MISC | LITERAL | PLACEHOLDER ) $/x; my %indents = ( select => 0, @@ -419,12 +420,16 @@ sub _recurse_parse { @right = $self->_recurse_parse($tokens, PARSE_IN_EXPR); } - @left = [$op => [ @left, @right ]]; + push @left, [$op => [ (@left ? pop @left : ''), @right ]]; } # unary op keywords elsif ( $token =~ $unary_op_re ) { my $op = uc $token; + + # normalize RNO explicitly + $op = 'ROW_NUMBER() OVER' if $op =~ /^$rno_re$/; + my @right = $self->_recurse_parse ($tokens, PARSE_RHS); push @left, [ $op => \@right ]; @@ -444,44 +449,61 @@ sub _recurse_parse { } # check if the current token is an unknown op-start - elsif (@$tokens and ($tokens->[0] eq '(' or $tokens->[0] =~ $common_single_args_re ) ) { + elsif (@$tokens and ($tokens->[0] eq '(' or $tokens->[0] =~ $placeholder_re ) ) { push @left, [ $token => [ $self->_recurse_parse($tokens, PARSE_RHS) ] ]; } # we're now in "unknown token" land - start eating tokens until - # we see something familiar + # we see something familiar, OR in the case of RHS (binop) stop + # after the first token + # Also stop processing when we could end up with an unknown func else { my @lits = [ -LITERAL => [$token] ]; - while (@$tokens and $tokens->[0] !~ $all_std_keywords_re) { - push @lits, [ -LITERAL => [ shift @$tokens ] ]; - } + unshift @lits, pop @left if @left == 1; - if (@left == 1) { - unshift @lits, pop @left; - } + unless ( $state == PARSE_RHS ) { + while ( + @$tokens + and + $tokens->[0] !~ $all_std_keywords_re + and + ! ( @$tokens > 1 and $tokens->[1] eq '(' ) + ) { + push @lits, [ -LITERAL => [ shift @$tokens ] ]; + } + } @lits = [ -MISC => [ @lits ] ] if @lits > 1; push @left, @lits; } - # deal with post-fix operators (only when sql is sane - i.e. we have one element to apply to) - if (@left == 1 and @$tokens) { - - # asc/desc - if ($tokens->[0] =~ $asc_desc_re) { - my $op = shift @$tokens; - - # if -MISC - this is a literal collection, do not promote asc/desc to an op - if ($left[0][0] eq '-MISC') { - push @{$left[0][1]}, [ -LITERAL => [ $op ] ]; + # compress -LITERAL -MISC and -PLACEHOLDER pieces into a single + # -MISC container + if (@left > 1) { + my $i = 0; + while ($#left > $i) { + if ($left[$i][0] =~ $compressable_node_re and $left[$i+1][0] =~ $compressable_node_re) { + splice @left, $i, 2, [ -MISC => [ + map { $_->[0] eq '-MISC' ? @{$_->[1]} : $_ } (@left[$i, $i+1]) + ]]; } else { - @left = [ ('-' . uc ($op)) => [ @left ] ]; + $i++; } } } + + return @left if $state == PARSE_RHS; + + # deal with post-fix operators + if (@$tokens) { + # asc/desc + if ($tokens->[0] =~ $asc_desc_re) { + @left = [ ('-' . uc (shift @$tokens)) => [ @left ] ]; + } + } } } @@ -596,14 +618,17 @@ sub _unparse { } else { my ($l, $r) = @{$self->pad_keyword($op, $depth)}; - return sprintf "$l%s%s%s$r", - $self->format_keyword($op), + + my $rhs = $self->_unparse($args, $bindargs, $depth); + + return sprintf "$l%s$r", join( ( ref $args eq 'ARRAY' and @{$args} == 1 and $args->[0][0] eq '-PAREN' ) ? '' # mysql-- : ' ' , - $self->_unparse($args, $bindargs, $depth), - ; + $self->format_keyword($op), + (length $rhs ? $rhs : () ), + ); } } @@ -639,12 +664,12 @@ sub _parenthesis_unroll { } # unroll nested parenthesis - while ( @{$child->[1]} == 1 and $child->[1][0][0] eq '-PAREN') { + while ( $ast->[0] ne 'IN' and @{$child->[1]} == 1 and $child->[1][0][0] eq '-PAREN') { $child = $child->[1][0]; $changes++; } - # if the parent operator explcitly allows it nuke the parenthesis + # if the parent operator explicitly allows it nuke the parenthesis if ( $ast->[0] =~ $unrollable_ops_re ) { push @children, @{$child->[1]}; $changes++; @@ -695,9 +720,9 @@ sub _parenthesis_unroll { @{$child->[1][0][1]} == 2 and ! ( - $child->[1][0][0] =~ $math_op_re + $child->[1][0][0] =~ $alphanum_cmp_op_re and - $ast->[0] =~ $math_op_re + $ast->[0] =~ $alphanum_cmp_op_re ) ) { push @children, @{$child->[1]}; @@ -715,9 +740,9 @@ sub _parenthesis_unroll { and @{$child->[1][0][1]} == 1 and - $ast->[0] =~ $math_op_re + $ast->[0] =~ $alphanum_cmp_op_re and - $child->[1][0][0] !~ $math_op_re + $child->[1][0][0] !~ $alphanum_cmp_op_re and ( $child->[1][0][1][0][0] eq '-PAREN' @@ -731,6 +756,23 @@ sub _parenthesis_unroll { $changes++; } + # a construct of ... ( somefunc ( ... ) ) ... can safely lose the outer parens + # except for the case of ( NOT ( ... ) ) which has already been handled earlier + elsif ( + @{$child->[1]} == 1 + and + @{$child->[1][0][1]} == 1 + and + $child->[1][0][0] ne 'NOT' + and + ref $child->[1][0][1][0] eq 'ARRAY' + and + $child->[1][0][1][0][0] eq '-PAREN' + ) { + push @children, @{$child->[1]}; + $changes++; + } + # otherwise no more mucking for this pass else { @@ -743,6 +785,30 @@ sub _parenthesis_unroll { } while ($changes); } +sub _strip_asc_from_order_by { + my ($self, $ast) = @_; + + return $ast if ( + ref $ast ne 'ARRAY' + or + $ast->[0] ne 'ORDER BY' + ); + + + my $to_replace; + + if (@{$ast->[1]} == 1 and $ast->[1][0][0] eq '-ASC') { + $to_replace = [ $ast->[1][0] ]; + } + elsif (@{$ast->[1]} == 1 and $ast->[1][0][0] eq '-LIST') { + $to_replace = [ grep { $_->[0] eq '-ASC' } @{$ast->[1][0][1]} ]; + } + + @$_ = @{$_->[1][0]} for @$to_replace; + + $ast; +} + sub format { my $self = shift; $self->unparse($self->parse($_[0]), $_[1]) } 1;