Query builder for Postgres backed by SQL parser
BSD-2-CLAUSE License
This is a query builder for Postgres with a twist: it contains a partial1 reimplementation of PostgreSQL's own query parser. This sets it aside from the usual breed of "write-only" query builders:
:foo
instead of standard PostgreSQL's positional parameters $1
and to infer parameters' typesSELECT
(and VALUES
) / INSERT
/ UPDATE
/ DELETE
/ MERGE
in PostgreSQL 16Substantial effort was made to optimise parsing, but not parsing is faster anyway, so there are means to cache parts of AST and the resultant query.
use sad_spirit\pg_builder\{
Select,
StatementFactory,
converters\BuilderSupportDecorator
};
use sad_spirit\pg_wrapper\{
Connection,
converters\DefaultTypeConverterFactory
};
$wantPDO = false;
if ($wantPDO) {
$pdo = new \PDO('pgsql:host=localhost;user=username;dbname=cms');
// Uses DB connection properties to set up parsing and building of SQL
$factory = StatementFactory::forPDO($pdo);
// NB: This still requires sad_spirit/pg_wrapper for type conversion code
$converter = new BuilderSupportDecorator(new DefaultTypeConverterFactory(), $factory->getParser());
} else {
$connection = new Connection('host=localhost user=username dbname=cms');
// Uses DB connection properties to set up parsing and building of SQL
$factory = StatementFactory::forConnection($connection);
// Needed for handling type info extracted from query
$connection->setTypeConverterFactory(new BuilderSupportDecorator(
$connection->getTypeConverterFactory(),
$factory->getParser()
));
}
// latest 5 news
/** @var Select $query */
$query = $factory->createFromString(
'select n.* from news as n order by news_added desc limit 5'
);
// we also need pictures for these...
$query->list[] = 'p.*';
$query->from[0]->leftJoin('pictures as p')->on = 'n.picture_id = p.picture_id';
// ...and need to limit them to only specific rubrics
$query->from[] = 'objects_rubrics as ro';
$query->where->and('ro.rubric_id = any(:rubric::integer[]) and ro.obj_id = n.news_id');
// ...and keep 'em fresh
$query->where->and('age(news_added) < :age::interval');
// $generated contains a query, mapping from named parameters to positional ones, types info
// it can be easily cached to prevent parsing/building SQL on each request
$generated = $factory->createFromAST($query);
// Note that we don't have to specify parameter types, these are extracted from query
if ($wantPDO) {
$result = $pdo->prepare($generated->getSql());
$result->execute($converter->convertParameters(
$generated,
[
'rubric' => [19, 20, 21],
'age' => 30 * 24 * 3600
]
));
} else {
$result = $generated->executeParams(
$connection,
[
'rubric' => [19, 20, 21],
'age' => 30 * 24 * 3600
]
);
}
foreach ($result as $row) {
print_r($row);
}
echo $generated->getSql();
the last echo
statement will output something like
select n.*, p.*
from news as n left join pictures as p on n.picture_id = p.picture_id, objects_rubrics as ro
where ro.rubric_id = any($1::pg_catalog.int4[])
and ro.obj_id = n.news_id
and age(news_added) < $2::interval
order by news_added desc
limit 5
if targeting Connection
and something like
select n.*, p.*
from news as n left join pictures as p on n.picture_id = p.picture_id, objects_rubrics as ro
where ro.rubric_id = any(:rubric::pg_catalog.int4[])
and ro.obj_id = n.news_id
and age(news_added) < :age::interval
order by news_added desc
limit 5
if targeting PDO
Is in the wiki
1: "Partial" here means the following: PostgreSQL grammar file src/backend/parser/gram.y
is about 19K lines long.
Of these about 5K lines are used for SELECT
/ INSERT
/ UPDATE
/ DELETE
/ MERGE
queries and are reimplemented here.