def clear(self):
"""Remove all entries from the database. This operation can be undone
using the :meth:`undo` method.
"""
cmds = CompositeOperation()
for entry in self:
for tag in entry.tags:
cmds.add(commands.RemoveTag(self.session, entry, tag))
# TODO: also remove all FITS header entries and all FITS header
# comments from each entry before removing the entry itself!
# remove all entries from all helper tables
database_tables = [
tables.JSONDump, tables.Tag, tables.FitsHeaderEntry,
tables.FitsKeyComment
]
for table in database_tables:
for entry in self.session.query(table):
cmds.add(commands.RemoveEntry(self.session, entry))
for entry in self:
cmds.add(commands.RemoveEntry(self.session, entry))
del self._cache[entry.id]
if self._enable_history:
self._command_manager.do(cmds)
else:
cmds()
def remove_tag(self, database_entry, tag_name):
"""Remove the given tag from the database entry. If the tag is not
connected to any entry after this operation, the tag itself is removed
from the database as well.
Raises
------
sunpy.database.NoSuchTagError
If the tag is not connected to the given entry.
"""
tag = self.get_tag(tag_name)
cmds = CompositeOperation()
remove_tag_cmd = commands.RemoveTag(self.session, database_entry, tag)
remove_tag_cmd()
if self._enable_history:
cmds.add(remove_tag_cmd)
if not tag.data:
remove_entry_cmd = commands.RemoveEntry(self.session, tag)
remove_entry_cmd()
if self._enable_history:
cmds.add(remove_entry_cmd)
if self._enable_history:
self._command_manager.push_undo_command(cmds)