public function Schema::queryTableInformation in Drupal 8

Same name and namespace in other branches

1. 9 core/lib/Drupal/Core/Database/Driver/pgsql/Schema.php \Drupal\Core\Database\Driver\pgsql\Schema::queryTableInformation()

Fetch the list of blobs and sequences used on a table.

We introspect the database to collect the information required by insert and update queries.

Parameters

$table_name: The non-prefixed name of the table.

Return value

An object with two member variables:

• 'blob_fields' that lists all the blob fields in the table.
• 'sequences' that lists the sequences used in that table.

2 calls to Schema::queryTableInformation()

Schema::changeField in core/lib/Drupal/Core/Database/Driver/pgsql/Schema.php

Change a field definition.

Schema::renameTable in core/lib/Drupal/Core/Database/Driver/pgsql/Schema.php

Rename a table.

File

core/lib/Drupal/Core/Database/Driver/pgsql/Schema.php, line 108

Class

Schema

PostgreSQL implementation of \Drupal\Core\Database\Schema.

Namespace

Drupal\Core\Database\Driver\pgsql

Code

public function queryTableInformation($table) {

  // Generate a key to reference this table's information on.
  $key = $this->connection
    ->prefixTables('{' . $table . '}');

  // Take into account that temporary tables are stored in a different schema.
  // \Drupal\Core\Database\Connection::generateTemporaryTableName() sets the
  // 'db_temporary_' prefix to all temporary tables.
  if (strpos($key, '.') === FALSE && strpos($table, 'db_temporary_') === FALSE) {
    $key = 'public.' . $key;
  }
  else {
    $key = $this
      ->getTempNamespaceName() . '.' . $key;
  }
  if (!isset($this->tableInformation[$key])) {
    $table_information = (object) [
      'blob_fields' => [],
      'sequences' => [],
    ];
    $this->connection
      ->addSavepoint();
    try {

      // The bytea columns and sequences for a table can be found in
      // pg_attribute, which is significantly faster than querying the
      // information_schema. The data type of a field can be found by lookup
      // of the attribute ID, and the default value must be extracted from the
      // node tree for the attribute definition instead of the historical
      // human-readable column, adsrc.
      $sql = <<<'EOD'
SELECT pg_attribute.attname AS column_name, format_type(pg_attribute.atttypid, pg_attribute.atttypmod) AS data_type, pg_get_expr(pg_attrdef.adbin, pg_attribute.attrelid) AS column_default
FROM pg_attribute
LEFT JOIN pg_attrdef ON pg_attrdef.adrelid = pg_attribute.attrelid AND pg_attrdef.adnum = pg_attribute.attnum
WHERE pg_attribute.attnum > 0
AND NOT pg_attribute.attisdropped
AND pg_attribute.attrelid = :key::regclass
AND (format_type(pg_attribute.atttypid, pg_attribute.atttypmod) = 'bytea'
OR pg_get_expr(pg_attrdef.adbin, pg_attribute.attrelid) LIKE 'nextval%')
EOD;
      $result = $this->connection
        ->query($sql, [
        ':key' => $key,
      ]);
    } catch (\Exception $e) {
      $this->connection
        ->rollbackSavepoint();
      throw $e;
    }
    $this->connection
      ->releaseSavepoint();

    // If the table information does not yet exist in the PostgreSQL
    // metadata, then return the default table information here, so that it
    // will not be cached.
    if (empty($result)) {
      return $table_information;
    }
    foreach ($result as $column) {
      if ($column->data_type == 'bytea') {
        $table_information->blob_fields[$column->column_name] = TRUE;
      }
      elseif (preg_match("/nextval\\('([^']+)'/", $column->column_default, $matches)) {

        // We must know of any sequences in the table structure to help us
        // return the last insert id. If there is more than 1 sequences the
        // first one (index 0 of the sequences array) will be used.
        $table_information->sequences[] = $matches[1];
        $table_information->serial_fields[] = $column->column_name;
      }
    }
    $this->tableInformation[$key] = $table_information;
  }
  return $this->tableInformation[$key];
}