Issue #3155563 by mcdruid, mrinalini9, Hardik_Patel_12, mondrake, daffie:...

Issue #3155563 by mcdruid, mrinalini9, Hardik_Patel_12, mondrake, daffie: select query should quote aliases which are reserved words in MySQL

core/lib/Drupal/Core/Database/Query/Select.php

@@ -807,13 +807,15 @@ public function __toString() {
     $fields = [];
     foreach ($this->tables as $alias => $table) {
       if (!empty($table['all_fields'])) {
-        $fields[] = $this->connection->escapeTable($alias) . '.*';
+        $fields[] = $this->connection->escapeAlias($alias) . '.*';
       }
     }
     foreach ($this->fields as $field) {
+      // Note that $field['table'] holds the table_alias.
+      // @see \Drupal\Core\Database\Query\Select::addField
+      $table = isset($field['table']) ? $field['table'] . '.' : '';
       // Always use the AS keyword for field aliases, as some
       // databases require it (e.g., PostgreSQL).
-      $table = isset($field['table']) ? $field['table'] . '.' : '';
       $fields[] = $this->connection->escapeField($table . $field['field']) . ' AS ' . $this->connection->escapeAlias($field['alias']);
     }
     foreach ($this->expressions as $expression) {

core/modules/system/tests/modules/database_test/database_test.install

@@ -331,6 +331,22 @@ function database_test_schema() {
     'primary key' => ['id'],
   ];
 
+  $schema['virtual'] = [
+    'description' => 'A simple table with reserved name in MySQL 8.',
+    'fields' => [
+      'id' => [
+        'description' => 'Simple unique ID.',
+        'type' => 'int',
+        'not null' => TRUE,
+      ],
+      'function' => [
+        'description' => 'A column with reserved name in MySQL 8.',
+        'type' => 'text',
+      ],
+    ],
+    'primary key' => ['id'],
+  ];
+
   $schema['TEST_UPPERCASE'] = $schema['test'];
 
   return $schema;

core/tests/Drupal/KernelTests/Core/Database/DatabaseTestBase.php

@@ -37,6 +37,7 @@ protected function setUp() {
       'test_serialized',
       'TEST_UPPERCASE',
       'select',
+      'virtual',
     ]);
     self::addSampleData();
   }
@@ -163,6 +164,13 @@ public static function addSampleData() {
         'update' => 'Update value 1',
       ])
       ->execute();
+
+    $connection->insert('virtual')
+      ->fields([
+        'id' => 1,
+        'function' => 'Function value 1',
+      ])
+      ->execute();
   }
 
 }

core/tests/Drupal/KernelTests/Core/Database/ReservedWordTest.php

+<?php
+
+namespace Drupal\KernelTests\Core\Database;
+
+/**
+ * Tests queries that include reserved words.
+ *
+ * @group Database
+ */
+class ReservedWordTest extends DatabaseTestBase {
+
+  /**
+   * Tests SELECT count query from a table with a reserved name.
+   */
+  public function testSelectReservedWordTableCount() {
+    $query = $this->connection->select('virtual');
+    $num_records = $query->countQuery()->execute()->fetchField();
+
+    $this->assertSame('1', $num_records);
+  }
+
+  /**
+   * Tests SELECT query with a specific field from a table with a reserved name.
+   */
+  public function testSelectReservedWordTableSpecificField() {
+    $query = $this->connection->select('virtual');
+    $query->addField('virtual', 'function');
+    $rows = $query->execute()->fetchCol();
+
+    $this->assertSame('Function value 1', $rows[0]);
+  }
+
+  /**
+   * Tests SELECT query with all fields from a table with a reserved name.
+   */
+  public function testSelectReservedWordTableAllFields() {
+    $query = $this->connection->select('virtual');
+    $query->fields('virtual');
+    $result = $query->execute()->fetchObject();
+
+    $this->assertSame('Function value 1', $result->function);
+  }
+
+  /**
+   * Tests SELECT count query from a table with a reserved alias.
+   */
+  public function testSelectReservedWordAliasCount() {
+    $query = $this->connection->select('test', 'character');
+    $num_records = $query->countQuery()->execute()->fetchField();
+
+    $this->assertSame('4', $num_records);
+  }
+
+  /**
+   * Tests SELECT query with specific fields from a table with a reserved alias.
+   */
+  public function testSelectReservedWordAliasSpecificFields() {
+    $query = $this->connection->select('test', 'high_priority');
+    $query->addField('high_priority', 'name');
+    $query->addField('high_priority', 'age', 'age');
+    $query->condition('age', 27);
+    $record = $query->execute()->fetchObject();
+
+    // Ensure that we got the right record.
+    $this->assertSame('George', $record->name);
+    $this->assertSame('27', $record->age);
+  }
+
+  /**
+   * Tests SELECT query with all fields from a table with a reserved alias.
+   */
+  public function testSelectReservedWordAliasAllFields() {
+    $record = $this->connection->select('test', 'signal')
+      ->fields('signal')
+      ->condition('age', 27)
+      ->execute()->fetchObject();
+
+    // Ensure that we got the right record.
+    $this->assertSame('George', $record->name);
+    $this->assertSame('27', $record->age);
+  }
+
+}