ENH Allow selecting multiple (or no) tables

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Guy Sartorelli 2023-08-04 15:38:28 +12:00
parent b8665a70d5
commit 09da83f1cd
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4 changed files with 127 additions and 19 deletions

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@ -242,9 +242,25 @@ class DBQueryBuilder
public function buildFromFragment(SQLConditionalExpression $query, array &$parameters)
{
$from = $query->getJoins($joinParameters);
$tables = [];
$joins = [];
// E.g. a naive "Select 1" statement is valid SQL
if (empty($from)) {
return '';
}
foreach ($from as $joinOrTable) {
if (preg_match(SQLConditionalExpression::getJoinRegex(), $joinOrTable)) {
$joins[] = $joinOrTable;
} else {
$tables[] = $joinOrTable;
}
}
$parameters = array_merge($parameters, $joinParameters);
$nl = $this->getSeparator();
return "{$nl}FROM " . implode(' ', $from);
return "{$nl}FROM " . implode(', ', $tables) . ' ' . implode(' ', $joins);
}
/**

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@ -8,7 +8,6 @@ namespace SilverStripe\ORM\Queries;
*/
abstract class SQLConditionalExpression extends SQLExpression
{
/**
* An array of WHERE clauses.
*
@ -226,7 +225,7 @@ abstract class SQLConditionalExpression extends SQLExpression
foreach ($this->from as $key => $tableClause) {
if (is_array($tableClause)) {
$table = '"' . $tableClause['table'] . '"';
} elseif (is_string($tableClause) && preg_match('/JOIN +("[^"]+") +(AS|ON) +/i', $tableClause ?? '', $matches)) {
} elseif (is_string($tableClause) && preg_match(self::getJoinRegex(), $tableClause ?? '', $matches)) {
$table = $matches[1];
} else {
$table = $tableClause;
@ -325,11 +324,16 @@ abstract class SQLConditionalExpression extends SQLExpression
return $from;
}
// shift the first FROM table out from so we only deal with the JOINs
reset($from);
$baseFromAlias = key($from ?? []);
$baseFrom = array_shift($from);
// Remove the regular FROM tables out so we only deal with the JOINs
$regularTables = [];
foreach ($from as $alias => $tableClause) {
if (is_string($tableClause) && !preg_match(self::getJoinRegex(), $tableClause)) {
$regularTables[$alias] = $tableClause;
unset($from[$alias]);
}
}
// Sort the joins
$this->mergesort($from, function ($firstJoin, $secondJoin) {
if (!is_array($firstJoin)
|| !is_array($secondJoin)
@ -341,11 +345,14 @@ abstract class SQLConditionalExpression extends SQLExpression
}
});
// Put the first FROM table back into the results
if (!empty($baseFromAlias) && !is_numeric($baseFromAlias)) {
$from = array_merge([$baseFromAlias => $baseFrom], $from);
} else {
array_unshift($from, $baseFrom);
// Put the regular FROM tables back into the results
$regularTables = array_reverse($regularTables, true);
foreach ($regularTables as $alias => $tableName) {
if (!empty($alias) && !is_numeric($alias)) {
$from = array_merge([$alias => $tableName], $from);
} else {
array_unshift($from, $tableName);
}
}
return $from;
@ -773,4 +780,12 @@ abstract class SQLConditionalExpression extends SQLExpression
$this->copyTo($update);
return $update;
}
/**
* Get the regular expression pattern used to identify JOIN statements
*/
public static function getJoinRegex(): string
{
return '/JOIN +.*? +(AS|ON|USING\(?) +/i';
}
}

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@ -162,6 +162,9 @@ class SQLSelect extends SQLConditionalExpression
$fields = [$fields];
}
foreach ($fields as $idx => $field) {
if ($field === '') {
continue;
}
$this->selectField($field, is_numeric($idx) ? null : $idx);
}
@ -713,4 +716,10 @@ class SQLSelect extends SQLConditionalExpression
$query->setLimit(1, $index);
return $query;
}
public function isEmpty()
{
// Empty if there's no select, or we're trying to select '*' but there's no FROM clause
return empty($this->select) || (empty($this->from) && array_key_exists('*', $this->select));
}
}

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@ -67,19 +67,80 @@ class SQLSelectTest extends SapphireTest
}
}
public function provideIsEmpty()
{
return [
[
'query' => new SQLSelect(),
'expected' => true,
],
[
'query' => new SQLSelect(from: 'someTable'),
'expected' => false,
],
[
'query' => new SQLSelect(''),
'expected' => true,
],
[
'query' => new SQLSelect('', 'someTable'),
'expected' => true,
],
[
'query' => new SQLSelect('column', 'someTable'),
'expected' => false,
],
[
'query' => new SQLSelect('value'),
'expected' => false,
],
];
}
/**
* @dataProvider provideIsEmpty
*/
public function testIsEmpty(SQLSelect $query, $expected)
{
$this->assertSame($expected, $query->isEmpty());
}
public function testEmptyQueryReturnsNothing()
{
$query = new SQLSelect();
$this->assertSQLEquals('', $query->sql($parameters));
}
public function testSelectFromBasicTable()
public function provideSelectFrom()
{
return [
[
'from' => ['MyTable'],
'expected' => 'SELECT * FROM MyTable',
],
[
'from' => ['MyTable', 'MySecondTable'],
'expected' => 'SELECT * FROM MyTable, MySecondTable',
],
[
'from' => ['MyTable', 'INNER JOIN AnotherTable on AnotherTable.ID = MyTable.SomeFieldID'],
'expected' => 'SELECT * FROM MyTable INNER JOIN AnotherTable on AnotherTable.ID = MyTable.SomeFieldID',
],
[
'from' => ['MyTable', 'MySecondTable', 'INNER JOIN AnotherTable on AnotherTable.ID = MyTable.SomeFieldID'],
'expected' => 'SELECT * FROM MyTable, MySecondTable INNER JOIN AnotherTable on AnotherTable.ID = MyTable.SomeFieldID',
],
];
}
/**
* @dataProvider provideSelectFrom
*/
public function testSelectFrom(array $from, string $expected)
{
$query = new SQLSelect();
$query->setFrom('MyTable');
$this->assertSQLEquals("SELECT * FROM MyTable", $query->sql($parameters));
$query->addFrom('MyJoin');
$this->assertSQLEquals("SELECT * FROM MyTable MyJoin", $query->sql($parameters));
$query->setFrom($from);
$this->assertSQLEquals($expected, $query->sql($parameters));
}
public function testSelectFromUserSpecifiedFields()
@ -724,6 +785,13 @@ class SQLSelectTest extends SapphireTest
);
}
public function testSelectWithNoTable()
{
$query = new SQLSelect('200');
$this->assertSQLEquals('SELECT 200 AS "200"', $query->sql());
$this->assertSame([['200' => 200]], iterator_to_array($query->execute(), true));
}
/**
* Test passing in a LIMIT with OFFSET clause string.
*/
@ -819,12 +887,12 @@ class SQLSelectTest extends SapphireTest
// In SS4 the "explicitAlias" would be ignored
$query = SQLSelect::create('*', [
'MyTableAlias' => '"MyTable"',
'explicitAlias' => ', (SELECT * FROM "MyTable" where "something" = "whatever") as "CrossJoin"'
'explicitAlias' => '(SELECT * FROM "MyTable" where "something" = "whatever") as "CrossJoin"'
]);
$sql = $query->sql();
$this->assertSQLEquals(
'SELECT * FROM "MyTable" AS "MyTableAlias" , ' .
'SELECT * FROM "MyTable" AS "MyTableAlias", ' .
'(SELECT * FROM "MyTable" where "something" = "whatever") as "CrossJoin" AS "explicitAlias"',
$sql
);