--- /dev/null
+<?php
+
+namespace Drupal\KernelTests\Core\Database;
+
+/**
+ * Tests the Select query builder.
+ *
+ * @group Database
+ */
+class SelectSubqueryTest extends DatabaseTestBase {
+
+ /**
+ * Tests that we can use a subquery in a FROM clause.
+ */
+ public function testFromSubquerySelect() {
+ // Create a subquery, which is just a normal query object.
+ $subquery = db_select('test_task', 'tt');
+ $subquery->addField('tt', 'pid', 'pid');
+ $subquery->addField('tt', 'task', 'task');
+ $subquery->condition('priority', 1);
+
+ for ($i = 0; $i < 2; $i++) {
+ // Create another query that joins against the virtual table resulting
+ // from the subquery.
+ $select = db_select($subquery, 'tt2');
+ $select->join('test', 't', 't.id=tt2.pid');
+ $select->addField('t', 'name');
+ if ($i) {
+ // Use a different number of conditions here to confuse the subquery
+ // placeholder counter, testing https://www.drupal.org/node/1112854.
+ $select->condition('name', 'John');
+ }
+ $select->condition('task', 'code');
+
+ // The resulting query should be equivalent to:
+ // SELECT t.name
+ // FROM (SELECT tt.pid AS pid, tt.task AS task FROM test_task tt WHERE priority=1) tt
+ // INNER JOIN test t ON t.id=tt.pid
+ // WHERE tt.task = 'code'
+ $people = $select->execute()->fetchCol();
+
+ $this->assertCount(1, $people, 'Returned the correct number of rows.');
+ }
+ }
+
+ /**
+ * Tests that we can use a subquery in a FROM clause with a LIMIT.
+ */
+ public function testFromSubquerySelectWithLimit() {
+ // Create a subquery, which is just a normal query object.
+ $subquery = db_select('test_task', 'tt');
+ $subquery->addField('tt', 'pid', 'pid');
+ $subquery->addField('tt', 'task', 'task');
+ $subquery->orderBy('priority', 'DESC');
+ $subquery->range(0, 1);
+
+ // Create another query that joins against the virtual table resulting
+ // from the subquery.
+ $select = db_select($subquery, 'tt2');
+ $select->join('test', 't', 't.id=tt2.pid');
+ $select->addField('t', 'name');
+
+ // The resulting query should be equivalent to:
+ // SELECT t.name
+ // FROM (SELECT tt.pid AS pid, tt.task AS task FROM test_task tt ORDER BY priority DESC LIMIT 1 OFFSET 0) tt
+ // INNER JOIN test t ON t.id=tt.pid
+ $people = $select->execute()->fetchCol();
+
+ $this->assertCount(1, $people, 'Returned the correct number of rows.');
+ }
+
+ /**
+ * Tests that we can use a subquery with an IN operator in a WHERE clause.
+ */
+ public function testConditionSubquerySelect() {
+ // Create a subquery, which is just a normal query object.
+ $subquery = db_select('test_task', 'tt');
+ $subquery->addField('tt', 'pid', 'pid');
+ $subquery->condition('tt.priority', 1);
+
+ // Create another query that joins against the virtual table resulting
+ // from the subquery.
+ $select = db_select('test_task', 'tt2');
+ $select->addField('tt2', 'task');
+ $select->condition('tt2.pid', $subquery, 'IN');
+
+ // The resulting query should be equivalent to:
+ // SELECT tt2.name
+ // FROM test tt2
+ // WHERE tt2.pid IN (SELECT tt.pid AS pid FROM test_task tt WHERE tt.priority=1)
+ $people = $select->execute()->fetchCol();
+ $this->assertCount(5, $people, 'Returned the correct number of rows.');
+ }
+
+ /**
+ * Test that we can use a subquery with a relational operator in a WHERE clause.
+ */
+ public function testConditionSubquerySelect2() {
+ // Create a subquery, which is just a normal query object.
+ $subquery = db_select('test', 't2');
+ $subquery->addExpression('AVG(t2.age)');
+
+ // Create another query that adds a clause using the subquery.
+ $select = db_select('test', 't');
+ $select->addField('t', 'name');
+ $select->condition('t.age', $subquery, '<');
+
+ // The resulting query should be equivalent to:
+ // SELECT t.name
+ // FROM test t
+ // WHERE t.age < (SELECT AVG(t2.age) FROM test t2)
+ $people = $select->execute()->fetchCol();
+ $this->assertEquals(['John', 'Paul'], $people, 'Returned Paul and John.', 0.0, 10, TRUE);
+ }
+
+ /**
+ * Test that we can use 2 subqueries with a relational operator in a WHERE clause.
+ */
+ public function testConditionSubquerySelect3() {
+ // Create subquery 1, which is just a normal query object.
+ $subquery1 = db_select('test_task', 'tt');
+ $subquery1->addExpression('AVG(tt.priority)');
+ $subquery1->where('tt.pid = t.id');
+
+ // Create subquery 2, which is just a normal query object.
+ $subquery2 = db_select('test_task', 'tt2');
+ $subquery2->addExpression('AVG(tt2.priority)');
+
+ // Create another query that adds a clause using the subqueries.
+ $select = db_select('test', 't');
+ $select->addField('t', 'name');
+ $select->condition($subquery1, $subquery2, '>');
+
+ // The resulting query should be equivalent to:
+ // SELECT t.name
+ // FROM test t
+ // WHERE (SELECT AVG(tt.priority) FROM test_task tt WHERE tt.pid = t.id) > (SELECT AVG(tt2.priority) FROM test_task tt2)
+ $people = $select->execute()->fetchCol();
+ $this->assertEquals(['John'], $people, 'Returned John.', 0.0, 10, TRUE);
+ }
+
+ /**
+ * Test that we can use multiple subqueries.
+ *
+ * This test uses a subquery at the left hand side and multiple subqueries at
+ * the right hand side. The test query may not be that logical but that's due
+ * to the limited amount of data and tables. 'Valid' use cases do exist :)
+ */
+ public function testConditionSubquerySelect4() {
+ // Create subquery 1, which is just a normal query object.
+ $subquery1 = db_select('test_task', 'tt');
+ $subquery1->addExpression('AVG(tt.priority)');
+ $subquery1->where('tt.pid = t.id');
+
+ // Create subquery 2, which is just a normal query object.
+ $subquery2 = db_select('test_task', 'tt2');
+ $subquery2->addExpression('MIN(tt2.priority)');
+ $subquery2->where('tt2.pid <> t.id');
+
+ // Create subquery 3, which is just a normal query object.
+ $subquery3 = db_select('test_task', 'tt3');
+ $subquery3->addExpression('AVG(tt3.priority)');
+ $subquery3->where('tt3.pid <> t.id');
+
+ // Create another query that adds a clause using the subqueries.
+ $select = db_select('test', 't');
+ $select->addField('t', 'name');
+ $select->condition($subquery1, [$subquery2, $subquery3], 'BETWEEN');
+
+ // The resulting query should be equivalent to:
+ // SELECT t.name AS name
+ // FROM {test} t
+ // WHERE (SELECT AVG(tt.priority) AS expression FROM {test_task} tt WHERE (tt.pid = t.id))
+ // BETWEEN (SELECT MIN(tt2.priority) AS expression FROM {test_task} tt2 WHERE (tt2.pid <> t.id))
+ // AND (SELECT AVG(tt3.priority) AS expression FROM {test_task} tt3 WHERE (tt3.pid <> t.id));
+ $people = $select->execute()->fetchCol();
+ $this->assertEquals(['George', 'Paul'], $people, 'Returned George and Paul.', 0.0, 10, TRUE);
+ }
+
+ /**
+ * Tests that we can use a subquery in a JOIN clause.
+ */
+ public function testJoinSubquerySelect() {
+ // Create a subquery, which is just a normal query object.
+ $subquery = db_select('test_task', 'tt');
+ $subquery->addField('tt', 'pid', 'pid');
+ $subquery->condition('priority', 1);
+
+ // Create another query that joins against the virtual table resulting
+ // from the subquery.
+ $select = db_select('test', 't');
+ $select->join($subquery, 'tt', 't.id=tt.pid');
+ $select->addField('t', 'name');
+
+ // The resulting query should be equivalent to:
+ // SELECT t.name
+ // FROM test t
+ // INNER JOIN (SELECT tt.pid AS pid FROM test_task tt WHERE priority=1) tt ON t.id=tt.pid
+ $people = $select->execute()->fetchCol();
+
+ $this->assertCount(2, $people, 'Returned the correct number of rows.');
+ }
+
+ /**
+ * Tests EXISTS subquery conditionals on SELECT statements.
+ *
+ * We essentially select all rows from the {test} table that have matching
+ * rows in the {test_people} table based on the shared name column.
+ */
+ public function testExistsSubquerySelect() {
+ // Put George into {test_people}.
+ db_insert('test_people')
+ ->fields([
+ 'name' => 'George',
+ 'age' => 27,
+ 'job' => 'Singer',
+ ])
+ ->execute();
+ // Base query to {test}.
+ $query = db_select('test', 't')
+ ->fields('t', ['name']);
+ // Subquery to {test_people}.
+ $subquery = db_select('test_people', 'tp')
+ ->fields('tp', ['name'])
+ ->where('tp.name = t.name');
+ $query->exists($subquery);
+ $result = $query->execute();
+
+ // Ensure that we got the right record.
+ $record = $result->fetch();
+ $this->assertEquals('George', $record->name, 'Fetched name is correct using EXISTS query.');
+ }
+
+ /**
+ * Tests NOT EXISTS subquery conditionals on SELECT statements.
+ *
+ * We essentially select all rows from the {test} table that don't have
+ * matching rows in the {test_people} table based on the shared name column.
+ */
+ public function testNotExistsSubquerySelect() {
+ // Put George into {test_people}.
+ db_insert('test_people')
+ ->fields([
+ 'name' => 'George',
+ 'age' => 27,
+ 'job' => 'Singer',
+ ])
+ ->execute();
+
+ // Base query to {test}.
+ $query = db_select('test', 't')
+ ->fields('t', ['name']);
+ // Subquery to {test_people}.
+ $subquery = db_select('test_people', 'tp')
+ ->fields('tp', ['name'])
+ ->where('tp.name = t.name');
+ $query->notExists($subquery);
+
+ // Ensure that we got the right number of records.
+ $people = $query->execute()->fetchCol();
+ $this->assertCount(3, $people, 'NOT EXISTS query returned the correct results.');
+ }
+
+}
projects / yaffs-website / blobdiff