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This cheat sheet provides an overview of commonly used methods, classes, and interfaces for content entities.

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/sites/default/files/drupal-content-entity-8.0.pdf

Any query can have a corresponding "count query". A count query returns the number of rows in the original query. To get a count query from an existing query (which is a select query object implementing the SelectInterface), use the countQuery() method.

This cheat sheet provides an overview of commonly used methods, classes, and interfaces for content entities.

Download

/sites/default/files/drupal-content-entity-8.0.pdf

This cheat sheet provides an overview of commonly used methods, classes, and interfaces for content entities.

Download

/sites/default/files/drupal-content-entity-8.0.pdf

Merge queries are a special type of hybrid query. Although the syntax for them is defined in the SQL 2003 specification, virtually no database supports the standard syntax. However, most provide an alternative implementation using database-specific syntax. Drupal’s merge query builder abstracts the concept of a merge query into a structured object that can be compiled into the appropriate syntax for each database. They are sometimes referred to as "UPSERT" queries, a combination of UPDATE and INSERT.

Select queries always return a result set object containing zero or more records. There are several ways to retrieve data from this result set depending on the use case. Records are fetched as objects by default unless you change the fetch mode (see: setFetchMode).

The most common use case is iterating over the result set with a foreach() loop.

This cheat sheet provides an overview of commonly used methods, classes, and interfaces for content entities.

Download

/sites/default/files/drupal-content-entity-8.0.pdf

Queries can be fetched into objects based on custom classes. For example, if we have a class named ExampleClass, the following query will return objects of type ExampleClass.

$result = $connection->query("SELECT id, title FROM {example_table}", [], [
  'fetch' => 'ExampleClass',
]);

If the class has a __construct() method, objects will be created, properties will be added to the object, and then the __construct() method will be called. For example, if you have the following class and query:

Insert queries should always use the query builder object. Some databases require special handling for LOB (Large OBject, e.g., TEXT in MySQL) and BLOB (Binary Large OBject) fields, so an abstraction layer is necessary for individual database drivers to implement any required special handling.

Insert queries are initiated using the insert() method like this:

Delete queries should always use the query builder object. They are initiated using the delete() method as follows:

$query = $connection->delete('mytable', $options);

This creates a delete query object that removes records from the mytable table. Note that curly braces are not required around the table name, as the query builder will handle this automatically.