108 lines
3.4 KiB
PHP
108 lines
3.4 KiB
PHP
<?php
|
|
|
|
namespace SilverStripe\PostgreSQL;
|
|
|
|
use SilverStripe\ORM\Queries\SQLConditionalExpression;
|
|
use SilverStripe\ORM\Queries\SQLExpression;
|
|
use SilverStripe\ORM\Queries\SQLSelect;
|
|
use SilverStripe\ORM\Connect\DBQueryBuilder;
|
|
use InvalidArgumentException;
|
|
|
|
class PostgreSQLQueryBuilder extends DBQueryBuilder
|
|
{
|
|
/**
|
|
* Max table length.
|
|
* Aliases longer than this will be re-written
|
|
*/
|
|
const MAX_TABLE = 63;
|
|
|
|
/**
|
|
* Return the LIMIT clause ready for inserting into a query.
|
|
*
|
|
* @param SQLSelect $query The expression object to build from
|
|
* @param array $parameters Out parameter for the resulting query parameters
|
|
* @return string The finalised limit SQL fragment
|
|
*/
|
|
public function buildLimitFragment(SQLSelect $query, array &$parameters)
|
|
{
|
|
$nl = $this->getSeparator();
|
|
|
|
// Ensure limit is given
|
|
$limit = $query->getLimit();
|
|
if (empty($limit)) {
|
|
return '';
|
|
}
|
|
|
|
// For literal values return this as the limit SQL
|
|
if (! is_array($limit)) {
|
|
return "{$nl}LIMIT $limit";
|
|
}
|
|
|
|
// Assert that the array version provides the 'limit' key
|
|
if (! array_key_exists('limit', $limit) || ($limit['limit'] !== null && ! is_numeric($limit['limit']))) {
|
|
throw new InvalidArgumentException(
|
|
'DBQueryBuilder::buildLimitSQL(): Wrong format for $limit: '. var_export($limit, true)
|
|
);
|
|
}
|
|
|
|
if ($limit['limit'] === null) {
|
|
$limit['limit'] = 'ALL';
|
|
}
|
|
|
|
$clause = "{$nl}LIMIT {$limit['limit']}";
|
|
if (isset($limit['start']) && is_numeric($limit['start']) && $limit['start'] !== 0) {
|
|
$clause .= " OFFSET {$limit['start']}";
|
|
}
|
|
return $clause;
|
|
}
|
|
|
|
public function buildSQL(SQLExpression $query, &$parameters)
|
|
{
|
|
$sql = parent::buildSQL($query, $parameters);
|
|
return $this->rewriteLongIdentifiers($query, $sql);
|
|
}
|
|
|
|
/**
|
|
* Find and generate table aliases necessary in the given query
|
|
*
|
|
* @param SQLConditionalExpression $query
|
|
* @return array List of replacements
|
|
*/
|
|
protected function findRewrites(SQLConditionalExpression $query)
|
|
{
|
|
$rewrites = [];
|
|
foreach ($query->getFrom() as $alias => $from) {
|
|
$table = is_array($from) ? $from['table'] : $from;
|
|
if ($alias === $table || "\"{$alias}\"" === $table) {
|
|
continue;
|
|
}
|
|
// Don't complain about aliases shorter than max length
|
|
if (strlen($alias) <= self::MAX_TABLE) {
|
|
continue;
|
|
}
|
|
$replacement = substr(sha1($alias), 0, 7) . '_' . substr($alias, 8 - self::MAX_TABLE);
|
|
$rewrites["\"{$alias}\""] = "\"{$replacement}\"";
|
|
}
|
|
return $rewrites;
|
|
}
|
|
|
|
/**
|
|
* Rewrite all ` AS "Identifier"` with strlen(Identifier) > 63
|
|
*
|
|
* @param SQLExpression $query
|
|
* @param string $sql
|
|
* @return string
|
|
*/
|
|
protected function rewriteLongIdentifiers(SQLExpression $query, $sql)
|
|
{
|
|
// Check if this query has aliases
|
|
if ($query instanceof SQLConditionalExpression) {
|
|
$rewrites = $this->findRewrites($query);
|
|
if ($rewrites) {
|
|
return str_replace(array_keys($rewrites), array_values($rewrites), $sql);
|
|
}
|
|
}
|
|
return $sql;
|
|
}
|
|
}
|