drupal_write_record

Definition

drupal_write_record($table, &$object, $update = array())
includes/common.inc, line 3236

Description

Save a record to the database based upon the schema.

Default values are filled in for missing items, and 'serial' (auto increment) types are filled in with IDs.

Parameters

$table The name of the table; this must exist in schema API.

$object The object to write. This is a reference, as defaults according to the schema may be filled in on the object, as well as ID on the serial type(s). Both array an object types may be passed.

$update If this is an update, specify the primary keys' field names. It is the caller's responsibility to know if a record for this object already exists in the database. If there is only 1 key, you may pass a simple string.

Return value

Failure to write a record will return FALSE. Otherwise SAVED_NEW or SAVED_UPDATED is returned depending on the operation performed. The $object parameter contains values for any serial fields defined by the $table. For example, $object->nid will be populated after inserting a new node.

Name	Description
Schema API	A Drupal schema definition is an array structure representing one or more tables and their related keys and indexes. A schema is defined by hook_schema(), which usually lives in a modulename.install file.

Code

<?php
function drupal_write_record($table, &$object, $update = array()) {
  // Standardize $update to an array.
  if (is_string($update)) {
    $update = array($update);
  }

  $schema = drupal_get_schema($table);
  if (empty($schema)) {
    return FALSE;
  }

  // Convert to an object if needed.
  if (is_array($object)) {
    $object = (object) $object;
    $array = TRUE;
  }
  else {
    $array = FALSE;
  }

  $fields = $defs = $values = $serials = $placeholders = array();

  // Go through our schema, build SQL, and when inserting, fill in defaults for
  // fields that are not set.
  foreach ($schema['fields'] as $field => $info) {
    // Special case -- skip serial types if we are updating.
    if ($info['type'] == 'serial' && count($update)) {
      continue;
    }

    // For inserts, populate defaults from Schema if not already provided
    if (!isset($object->$field) && !count($update) && isset($info['default'])) {
      $object->$field = $info['default'];
    }

    // Track serial fields so we can helpfully populate them after the query.
    if ($info['type'] == 'serial') {
      $serials[] = $field;
      // Ignore values for serials when inserting data. Unsupported.
      unset($object->$field);
    }

    // Build arrays for the fields, placeholders, and values in our query.
    if (isset($object->$field)) {
      $fields[] = $field;
      $placeholders[] = db_type_placeholder($info['type']);

      if (empty($info['serialize'])) {
        $values[] = $object->$field;
      }
      else {
        $values[] = serialize($object->$field);
      }
    }
  }

  // Build the SQL.
  $query = '';
  if (!count($update)) {
    $query = "INSERT INTO {". $table ."} (". implode(', ', $fields) .') VALUES ('. implode(', ', $placeholders) .')';
    $return = SAVED_NEW;
  }
  else {
    $query = '';
    foreach ($fields as $id => $field) {
      if ($query) {
        $query .= ', ';
      }
      $query .= $field .' = '. $placeholders[$id];
    }

    foreach ($update as $key){
      $conditions[] = "$key = ". db_type_placeholder($schema['fields'][$key]['type']);
      $values[] = $object->$key;
    }

    $query = "UPDATE {". $table ."} SET $query WHERE ". implode(' AND ', $conditions);
    $return = SAVED_UPDATED;
  }

  // Execute the SQL.
  if (db_query($query, $values)) {
    if ($serials) {
      // Get last insert ids and fill them in.
      foreach ($serials as $field) {
        $object->$field = db_last_insert_id($table, $field);
      }
    }
  }
  else {
    $return = FALSE;
  }

  // If we began with an array, convert back so we don't surprise the caller.
  if ($array) {
    $object = (array) $object;
  }

  return $return;
}
?>