Exception to deny attempts to explicitly manage transactions. This exception will be thrown when the PDO connection commit() is called. Code

public StatementInterface::fetchField($index = 0)

Exception thrown if an object being modified doesn't exist yet. For example, this exception should be thrown whenever there is an attempt to

An array of active query log objects. Every connection has one and only one logger object for all targets and logging keys.

Exception for when popTransaction() is called with no active transaction. Hierarchy class

Generic class for a series of conditions in a query. Hierarchy class \Drupal\Core\Database\Query\

public Query::uniqueIdentifier() Returns

public Condition::condition($field, $value = NULL, $operator = '=')

General class for an abstracted INSERT query. Hierarchy class \Drupal\Core\Database\Query\

public SelectExtender::conditionGroupFactory($conjunction =