join - PHP code example

PHP Function Join

Functions in PHP provide a powerful way to break complex tasks into smaller parts. It also helps to make code more modular and reusable.

In this article, we are going to discuss about the php function join which is used to combine the values of an array into a single string. This function works similar to the other built-in function in PHP called implode(). This function takes in two parameters - a separator and the array whose values it will combine to create a string. It also returns a string, but unlike the implode() function, this one allows you to use an empty string as a default delimiter for the array elements.

To understand the use of this function, lets take a look at some examples.

For example, if we have an array of five even numbers that need to be joined together, we would pass in the following script to the web server. The result will be a string that displays each value of the array with the hyphen (-) between them.

This type of join is referred to as an inner join. Using this technique you can retrieve data from multiple tables that are related to each other based on their common field. In addition, you can perform joins with more advanced SQL syntax like INNER JOIN, LEFT JOIN etc. Using the correct join types makes your database queries more readable and reduces Cartesian products in your database query results.

join example

'field_name',
        'type_name',
        'weight',
        'label',
        'display_settings',
        'widget_settings',
      ])
      ->fields('cnf', [
        'type',
        'module',
      ]);
    $query->join('content_node_field', 'cnf', '[cnfi].[field_name] = [cnf].[field_name]');
    $query->orderBy('cnfi.weight');

    return $query;
  }

  /** * {@inheritdoc} */
  public function fields() {
    return [
      'field_name' => $this->t('The machine name of field.'),

    protected function getDetailQuery($id)
    {
        $query = parent::getDetailQuery($id);

        return $this->addAssociations($query);
    }

    private function addAssociations(QueryBuilder $query): QueryBuilder
    {
        $query->addSelect(['country', 'state', 'PARTIAL customer.{id,email}'])
            ->join('address.customer', 'customer')
            ->join('address.country', 'country')
            ->leftJoin('address.state', 'state');

        return $query;
    }
}

$this->getAdminUiXmlSchema($pathToCustomEntityFile),
        );

        $this->customEntityPersister->update($customEntityXmlSchema->toStorage(), $extensionEntityType, $extensionId);
        $this->customEntitySchemaUpdater->update();

        return $customEntityXmlSchema;
    }

    private function getXmlSchema(string $pathToCustomEntityFile): ?CustomEntityXmlSchema
    {
        $filePath = Path::join($pathToCustomEntityFile, CustomEntityXmlSchema::FILENAME);
        if (!file_exists($filePath)) {
            return null;
        }

        $customEntityXmlSchema = CustomEntityXmlSchema::createFromXmlFile($filePath);
        $this->customEntityXmlSchemaValidator->validate($customEntityXmlSchema);

        return $customEntityXmlSchema;
    }

    private function getAdminUiXmlSchema(string $pathToCustomEntityFile): ?AdminUiXmlSchema
    {

    public function getElementDataQueryBuilder($elementId, $componentId)
    {
        $builder = $this->getEntityManager()->createQueryBuilder();
        $builder->select(['data.id', 'data.value', 'field.id as fieldId', 'field.name', 'field.valueType'])
            ->from(Data::class, 'data')
            ->join('data.field', 'field')
            ->leftJoin('field.component', 'component')
            ->where('component.id = ?1')
            ->andWhere('data.elementId = ?2')
            ->setParameter(1, $componentId)
            ->setParameter(2, $elementId);

        return $builder;
    }

    /** * @param int[] $elementIds * * @return array<int, list<array<string, mixed>>> indexed by elementId */

$this->assertEquals('sleep', $records[1]->{$task_field}, 'Correct data retrieved.');
  }

  /** * Tests that we can alter a query's conditionals. */
  public function testAlterChangeConditional() {
    $query = $this->connection->select('test_task');
    $tid_field = $query->addField('test_task', 'tid');
    $pid_field = $query->addField('test_task', 'pid');
    $task_field = $query->addField('test_task', 'task');
    $people_alias = $query->join('test', 'people', "[test_task].[pid] = [people].[id]");
    $name_field = $query->addField($people_alias, 'name', 'name');
    $query->condition('test_task.tid', '1');
    $query->orderBy($tid_field);
    $query->addTag('database_test_alter_change_conditional');

    $result = $query->execute();

    $records = $result->fetchAll();

    $this->assertCount(1, $records, 'Returned the correct number of rows.');
    $this->assertEquals('John', $records[0]->{$name_field}, 'Correct data retrieved.');

if ( $strict_guess ) {
            $where = $wpdb->prepare( 'post_name = %s', get_query_var( 'name' ) );
        } else {
            $where = $wpdb->prepare( 'post_name LIKE %s', $wpdb->esc_like( get_query_var( 'name' ) ) . '%' );
        }

        // If any of post_type, year, monthnum, or day are set, use them to refine the query.         if ( get_query_var( 'post_type' ) ) {
            if ( is_array( get_query_var( 'post_type' ) ) ) {
                // phpcs:ignore WordPress.DB.PreparedSQLPlaceholders.UnfinishedPrepare                 $where .= " AND post_type IN ('" . join( "', '", esc_sql( get_query_var( 'post_type' ) ) ) . "')";
            } else {
                $where .= $wpdb->prepare( ' AND post_type = %s', get_query_var( 'post_type' ) );
            }
        } else {
            $where .= " AND post_type IN ('" . implode( "', '", get_post_types( array( 'public' => true ) ) ) . "')";
        }

        if ( get_query_var( 'year' ) ) {
            $where .= $wpdb->prepare( ' AND YEAR(post_date) = %d', get_query_var( 'year' ) );
        }
        if ( get_query_var( 'monthnum' ) ) {

if($this->is_html || $this->is_text)
                trigger_error("Invalid content in element found. Content must not be of type text or html if it contains markup.");

            $attrs_prefix = array();

            // resolve prefixes for attributes             foreach($attrs as $key => $value) {
                $with_prefix = $this->ns_to_prefix($key, true);
                $attrs_prefix[$with_prefix[1]] = $this->xml_escape($value);
            }

            $attrs_str = join(' ', array_map($this->map_attrs_func, array_keys($attrs_prefix), array_values($attrs_prefix)));
            if(strlen($attrs_str) > 0) {
                $attrs_str = " " . $attrs_str;
            }

            $with_prefix = $this->ns_to_prefix($name);

            if(!$this->is_declared_content_ns($with_prefix[0])) {
                array_push($this->content_ns_decls, $with_prefix[0]);
            }

            $xmlns_str = '';

    }

    public function resolveField(Field $field, EntityDefinition $definition, string $root, QueryBuilder $query, Context $context): void
    {
        $resolver = $field->getResolver();

        if ($resolver === null) {
            return;
        }

        $resolver->join(new FieldResolverContext($root, $root, $field, $definition, $definition, $query, $context, null));
    }

    /** * Adds the full translation select part to the provided sql query. * Considers the parent-child inheritance and provided context language inheritance. * The raw parameter allows to skip the parent-child inheritance. * * @param array<string, mixed> $partial */
    public function addTranslationSelect(string $root, EntityDefinition $definition, QueryBuilder $query, Context $context, array $partial = []): void
    {

class FieldInstance extends DrupalSqlBase {

  /** * {@inheritdoc} */
  public function query() {
    $query = $this->select('content_node_field_instance', 'cnfi')->fields('cnfi');
    if (isset($this->configuration['node_type'])) {
      $query->condition('cnfi.type_name', $this->configuration['node_type']);
    }
    $query->join('content_node_field', 'cnf', '[cnf].[field_name] = [cnfi].[field_name]');
    $query->fields('cnf');
    $query->orderBy('cnfi.field_name');
    $query->orderBy('cnfi.type_name');

    return $query;
  }

  /** * {@inheritdoc} */
  public function fields() {

'a' => 'a'   , 'A' => 'a'   , 'B' => 'B'   , 'g' => 'h'   , 'G' => 'H'   , 'h' => 'hh'  ,
                         'H' => 'HH'  , 'i' => 'mm'  , 's' => 'ss'  , 'e' => 'zzzz', 'I' => 'I'   , 'O' => 'Z'   ,
                         'P' => 'ZZZZ', 'T' => 'z'   , 'Z' => 'X'   , 'c' => 'yyyy-MM-ddTHH:mm:ssZZZZ',
                         'r' => 'r'   , 'U' => 'U');
        $values = str_split($format);
        foreach ($values as $key => $value) {
            if (isset($convert[$value]) === true) {
                $values[$key] = $convert[$value];
            }
        }

        return join($values);
    }

    /** * Parse date and split in named array fields * * @param string $date Date string to parse * @param array $options Options: format_type, fix_date, locale, date_format. See {@link setOptions()} for details. * @return array Possible array members: day, month, year, hour, minute, second, fixed, format */
    private static function _parseDate($date, $options)
    {

->execute()
            ->fetchColumn();
    }

    /** * @return QueryBuilder */
    protected function getBaseQuery()
    {
        return $this->connection->createQueryBuilder()
            ->from('s_emotion', 'emo')
            ->join(
                'emo',
                's_emotion_categories',
                'emo_cat',
                'emo.id = emo_cat.emotion_id'
            )
            ->leftJoin('emo_cat', 's_categories', 'cat', 'emo_cat.category_id = cat.id')
            ->where('emo.active = 1')
            ->andWhere(sprintf('emo_cat.category_id IN (%s)', $this->prepareSubQuery()->getSQL()))
            ->andWhere('emo.valid_to > NOW() OR emo.valid_to IS NULL');
    }

public function getMaxTax()
    {
        $sessionId = $this->session->get('sessionId');
        if (!\is_string($sessionId)) {
            return false;
        }

        $qb = $this->connection->createQueryBuilder();
        $qb
            ->select(['product.taxID'])
            ->from('s_order_basket', 'basket')
            ->join('basket', 's_articles', 'product', 'product.id = basket.articleID')
            ->where($qb->expr()->andX(
                $qb->expr()->eq('basket.sessionID', ':sessionId'),
                $qb->expr()->eq('basket.modus', CartPositionsMode::PRODUCT)
            ))
            ->orderBy('basket.tax_rate', 'DESC')
            ->setMaxResults(1)
            ->setParameter('sessionId', $sessionId)
        ;

        $this->eventManager->notify(
            'Shopware_Modules_Basket_GetMaxTax_QueryBuilder',
            [

/** * {@inheritdoc} */
  public function query() {
    $query = $this->select('field_config_instance', 'fci')
      ->fields('fci')
      ->fields('fc', ['type', 'translatable'])
      ->condition('fc.active', 1)
      ->condition('fc.storage_active', 1)
      ->condition('fc.deleted', 0)
      ->condition('fci.deleted', 0);
    $query->join('field_config', 'fc', '[fci].[field_id] = [fc].[id]');

    // Optionally filter by entity type and bundle.     if (isset($this->configuration['entity_type'])) {
      $query->condition('fci.entity_type', $this->configuration['entity_type']);

      if (isset($this->configuration['bundle'])) {
        $query->condition('fci.bundle', $this->configuration['bundle']);
      }
    }

    // The Title module fields are not migrated.

$resolverContext = new FieldResolverContext(
            '',
            'document',
            $documentAssociationField,
            $documentDefinition,
            $orderDefinition,
            $this->queryBuilder,
            $this->context,
            null,
        );

        $this->resolver->join($resolverContext);

        static::assertSame([
            '`document`' => [
                [
                    'joinType' => 'left',
                    'joinTable' => '`order`',
                    'joinAlias' => '`document.order`',
                    'joinCondition' => '`document`.`order_id` = `document.order`.`id` AND `document`.`order_version_id` = `document.order`.`version_id`',
                ],
            ],
        ], $this->queryBuilder->getQueryPart('join'));
    }

public function prepareRow(Row $row) {
    $row->setSourceProperty('default_theme', $this->defaultTheme);
    $row->setSourceProperty('admin_theme', $this->adminTheme);

    $module = $row->getSourceProperty('module');
    $delta = $row->getSourceProperty('delta');

    $query = $this->select($this->blockRoleTable, 'br')
      ->fields('br', ['rid'])
      ->condition('module', $module)
      ->condition('delta', $delta);
    $query->join($this->userRoleTable, 'ur', '[br].[rid] = [ur].[rid]');
    $roles = $query->execute()
      ->fetchCol();
    $row->setSourceProperty('roles', $roles);

    $settings = [];
    switch ($module) {
      case 'aggregator':
        [$type, $id] = explode('-', $delta);
        if ($type == 'feed') {
          $item_count = $this->select('aggregator_feed', 'af')
            ->fields('af', ['block'])