hook_schema() Define the current version of the database schema. A Drupal schema

public &SelectInterface::getTables()

public AlterableInterface::hasTag($tag)

public PagerSelectExtender::element($element)

public Log::start($logging_key) Begin logging queries

public Insert::execute() Executes

protected Schema::createColumnsSql($tablename, $schema)

public Schema::addField($table, $field, $spec, $keys_new = array())

public Update::execute() Executes

Exception thrown if an insert query specifies a field twice. It is not allowed to specify a field as default and insert field, this exception