function dbtng_example_entry_load in Examples for Developers 7

Read from the database using a filter array.

In Drupal 6, the standard function to perform reads was db_query(), and for static queries, it still is.

db_query() used an SQL query with placeholders and arguments as parameters.

// Old way
$query = "SELECT * FROM {dbtng_example} n WHERE n.uid = %d AND name = '%s'";
$result = db_query($query, $uid, $name);

Drupal 7 DBTNG provides an abstracted interface that will work with a wide variety of database engines.

db_query() is deprecated except when doing a static query. The following is perfectly acceptable in Drupal 7. See the handbook page on static queries

// SELECT * FROM {dbtng_example} WHERE uid = 0 AND name = 'John'
db_query("SELECT * FROM {dbtng_example} WHERE uid = :uid and name = :name", array(
  ':uid' => 0,
  ':name' => 'John',
))
  ->execute();

But for more dynamic queries, Drupal provides the db_select() API method, so there are several ways to perform the same SQL query. See the handbook page on dynamic queries.

// SELECT * FROM {dbtng_example} WHERE uid = 0 AND name = 'John'
db_select('dbtng_example')
  ->fields('dbtng_example')
  ->condition('uid', 0)
  ->condition('name', 'John')
  ->execute();

Here is db_select with named placeholders:

// SELECT * FROM {dbtng_example} WHERE uid = 0 AND name = 'John'
$arguments = array(
  ':name' => 'John',
  ':uid' => 0,
);
db_select('dbtng_example')
  ->fields('dbtng_example')
  ->where('uid = :uid AND name = :name', $arguments)
  ->execute();

Conditions are stacked and evaluated as AND and OR depending on the type of query. For more information, read the conditional queries handbook page at: http://drupal.org/node/310086

The condition argument is an 'equal' evaluation by default, but this can be altered:

// SELECT * FROM {dbtng_example} WHERE age > 18
db_select('dbtng_example')
  ->fields('dbtng_example')
  ->condition('age', 18, '>')
  ->execute();

Parameters

array $entry: An array containing all the fields used to search the entries in the table.

Return value

object An object containing the loaded entries if found.

See also

db_select()

db_query()

http://drupal.org/node/310072

http://drupal.org/node/310075

Related topics

5 calls to dbtng_example_entry_load()

DBTNGExampleUnitTestCase::testAPIExamples in dbtng_example/dbtng_example.test

Test several combinations, adding entries, updating and deleting.

DBTNGExampleUnitTestCase::testInstall in dbtng_example/dbtng_example.test

Test default module installation, two entries in the database table.

DBTNGExampleUnitTestCase::testUI in dbtng_example/dbtng_example.test

Test the UI.

dbtng_example_form_update in dbtng_example/dbtng_example.module

Sample UI to update a record.

dbtng_example_list in dbtng_example/dbtng_example.module

Render a list of entries in the database.

File

dbtng_example/dbtng_example.module, line 247

This is an example outlining how a module can make use of the new DBTNG database API in Drupal 7.

Code

function dbtng_example_entry_load($entry = array()) {

  // Read all fields from the dbtng_example table.
  $select = db_select('dbtng_example', 'example');
  $select
    ->fields('example');

  // Add each field and value as a condition to this query.
  foreach ($entry as $field => $value) {
    $select
      ->condition($field, $value);
  }

  // Return the result in object format.
  return $select
    ->execute()
    ->fetchAll();
}