Sql abstract from_query

DépartementSQL::Abstract::FromQuery Office Building DB requests from Web queries Journées Perl 2012, Strasbourg laurent.dami@justice.ge.ch Département Office 29.06.12 - Page 1

Agenda• SQL::Abstract & SQL::Abstract::More• using SQLA::FromQuery – purpose – API• internals – Regexp::Grammars – multiple inheritance

Introduction : SQL::Abstract(::More)?

SQL::Abstract (SQLA) : examplemy $sqla = SQL::Abstract->new;my ($sql, @bind) = $sqla->select( $table_name, [qw/col1 col2 col3/], { col1 => val1, col2 => {-in => [qw/foo bar/]}, col3 => {-between => [qw/2012-01-01 2012-07-01/]}, col4 => {">" => 999}, col5 => {-like => foo%}, }, [qw/col1 col2/],);# SELECT col1, col2, col3 FROM $table_name# WHERE col1 = ? AND col2 IN (?, ?) AND col3 … etc# ORDER BY col1, col2

Purpose• generate SQL from Perl data structures – direct from config or from user input – avoid painful string manipulations with regex / join / etc.• placeholders and bind values – avoid datatype distinctions (strings / numbers /dates / etc.) – avoid SQL injection i  used by DBIx::Class, DBIx::DataModel, …

SQL::Abstract::More (SQLAM)• fully compatible with SQLA• named parameters• more SQL constructs (group by, limit/offset, union/intersect, etc.)• more syntax (aliases, joins, ordering direction, etc.)my $sqla = SQL::Abstract::More->new;my ($sql, @bind) = $sqla->select( -columns => [qw/table1.col|ct1 table2.col|ct2 … /], -from => $table_name, -where => { col1 => val1, col2 => {-in => [qw/foo bar/]}, … }, -union => [-columns => …, -from => …, -where => …], -order_by => [qw/+col1 -col2/],);

"Special operators" in SQLA• support for user-defined SQL extensions. For ex : – fulltext index – multivalued columns – case-insensitive – LIKE / GLOB / etc.• useful for DBMS-independent queries in apps – the "special operator" translates to DBMS-specific syntax{ col1 => {-contains => [qw/journées Perl/]}, col2 => {-anyval => [12, 34, 56]}, col3 => {-glob => foo*}, }

User input in complex search form Name : Smi*Gender : MSalary : > 4000 Job : ! programmer, analyst Birth : BETWEEN 01.01.1970 AND 31.12.1990Address: ! NULL not directly suitable for SQLA need translation to a Perl datastructure

Expected SQLA structure { Name => {-like => Smi%}, Gender => M, Salary => {> => 4000}, Job => {-not_in => [qw/programmer analyst/]}, Birth => {-between => [qw/1970-01-01 1990-12-31/]}, Address => {<> => undef}, }SELECT * FROM people WHERE Name LIKE Smi% AND Gender = M AND Salary > 4000 AND Job NOT IN (programmer, analyst) AND Birth BETWEEN 1970-01-01 AND 1990-12-31 AND Address IS NOT NULL

SQL::Abstract::FromQuery

Requirements• start from HTTP query object or from plain hashref• flexible syntax for user input – plain value – list of values – comparison operators – patterns – special constructs (BETWEEN, MATCH, etc.)• internationalization• DBMS-specific customizations• column declarations with specific behaviours – inject special ops – data conversion – etc.

APImy $parser = SQL::Abstract::FromQuery->new( # additional components (optional) -components => [qw/FR Oracle/], # grammar rules for some specific fields (optional) -fields => { standard => [qw/field1 field2 .../], bool => [qw/bool_field1/], ... } );try { my $where = $parser->parse($hashref || $http_query_object); … }catch { my $errors = $_; … };

Field types• Standard – a plain value (number, string, date or time). – a list of values, separated by ,. – a negated value or list of values; negation is expressed by ! or != or - or <> – a comparison operator <=, <, >=, > followed by a plain value – the special word NULL – BETWEEN val1 AND val2 – boolean values YES, NO, TRUE or FALSE• Restricted – string / bool / date / … (user-defined)

Components• FR – dates en format dd.mm.yyyy – mots-clés en français (VRAI, FAUX, ENTRE, NUL, etc.) – messages derreur en français• Oracle – queries on date and time • ["to_date(?, $date_format)", $date] • ["to_date(?, $time_format)", $date]  WHERE D_BIRTH > TO_DATE(DD.MM.YYYY, ?)• Contains – generate fulltext queries• … (user-defined)

Internals

Regexp::Grammarsuse Regexp::Grammars; qr{ <grammar: SQL::Abstract::FromQuery> <rule: standard> <MATCH=between> | <MATCH=op_and_value> | <MATCH=values> <rule: values> <[value]>+ % , <token: compare> <= | < | >= | > <rule: value> <MATCH=null> | <MATCH=date> | <MATCH=time> | <MATCH=string> <rule: date> <day=(dd?)>.<month=(dd?)>.<year=(ddd?d?)> | <year=(ddd?d?)>-<month=(dd?)>-<day=(dd?)>

Autoactions hooked to the grammarsub between { my ($self, $h) = @_; return {-between => [$h->{min}, $h->{max}]};}sub values { my ($self, $h) = @_; my $n_values = @{$h->{value}}; return $n_values > 1 ? {-in => $h->{value}} : $h->{value}[0];}

Inheritance<grammar: SQL::Abstract::FromQuery::FR><extends: SQL::Abstract::FromQuery><rule: null> NULL?<rule: between> <SQL::Abstract::FromQuery::between> | ENTRE (*COMMIT) (?: <min=value> ET <max=value> | <error:> )<rule: bool> O(?:UI)? (?{ $MATCH = 1 }) | V(?:RAI)? (?{ $MATCH = 1 }) | NO?N? (?{ $MATCH = 0 }) | F(?:AUX|ALSE)? (?{ $MATCH = 0 }) | Y(?:ES)? (?{ $MATCH = 1 })

Sql abstract from_query

by ldami on Jun 29, 2012

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