def getCount(cls, db, where = None):
"""Request number of records in this table.
"""
cls.checkTable(db)
count = cls.COUNT(where)
count = db.select(count, from_ = cls).value(0, count)
logger.debug('Model.getCount(%s, db= %s, where= %s) = %s' % (cls, db, where, count))
return count
def __new__(cls, name, bases, attrs):
NewModel = type.__new__(cls, name, bases, attrs)
NewModel._name = NewModel.__dict__.get('_name', name.lower()) # db table name
if NewModel._name is None: # we need only Model subclasses; if db table name is None - __new__ is called for Model itself
return NewModel # return without any processing
logger.debug('Finishing initialization of model `%s`' % NewModel)
# assure each class has its own attribute, because by default _indexes is inherited from the parent class
NewModel._indexes = list(NewModel._indexes)
attrs = OrderedDict(inspect.getmembers(NewModel))
fields = []
for fieldName, field in attrs.items():
if isinstance(field, orm.fields.Field):
fields.append((fieldName, field))
# sort by definition order (as __dict__ is unsorted) - for field recreation order
fields = OrderedDict(sorted(fields, key = lambda f: f[1]._id))
for fieldName, field in fields.items():
if not fieldName.islower() or fieldName.startswith('_'):
raise orm.ModelError('Field `%s` in model `%s`: field names must be lowercase and '
'must not start with `_`.' % (fieldName, name))
# recreate the field - to handle correctly inheritance of Tables
newField = field.__class__(name = fieldName, table = NewModel, label = field.label)
try:
newField._init_(*field._initArgs, **field._initKwargs) # and initialize it
except Exception:
print('Failed to init a field:', fieldName, field._initArgs, field._initKwargs)
raise
# each class has its own field object. Inherited and parent tables do not share field attributes
setattr(NewModel, fieldName, newField)
indexesDict = OrderedDict() # to filter duplicate indexes by index name
for index in NewModel._indexes:
if index.table is not NewModel: # inherited index
if not isinstance(index, orm.Index):
raise orm.ModelError('Found a non Index in the _indexes.')
if index.table is not NewModel:
# index was inherited from parent model - recreate it with fields from new model
indexFields = [orm.IndexField(NewModel[indexField.field.name], indexField.sortOrder, indexField.prefixLength)
for indexField in index.indexFields] # replace fields by name with fields from new model
index = orm.Index(indexFields, index.type, index.name, index.method, **index.other)
for indexField in index.indexFields:
if issubclass(NewModel, indexField.field.table):
indexField.field = NewModel[indexField.field.name] # to assure that field from this model, and from parent, is used
else:
raise orm.ModelError('Field `%s` in index is not from model `%s`.' % (indexField.field, NewModel))
indexesDict[index.name] = index
NewModel._indexes = indexesDict.values()
NewModel._ordering = list()
NewModel._checkedDbs = set()
return NewModel
def _execute(self, *a, **b):
query = a[0]
logger.debug('DB query: %s' % query)
t0 = time.time()
try:
result = self.cursor.execute(*a, **b)
except Exception:
logger.warning(query)
raise
self._timings.append((query, round(time.time() - t0, 4)))
return result
def __init__(self, uri = '', connect = True, autocommit = True):
"""URI is already without protocol."""
self.uri = uri
logger.debug('Creating adapter for `%s`' % self)
self._timings = []
if connect:
self.connection = self.connect()
self.cursor = self.connection.cursor()
else:
self.connection = None
self.cursor = None
self.autocommit = autocommit
def getColumns(self, tableName):
"""Get columns of a table"""
self.execute("PRAGMA table_info('%s')" % tableName) # name, type, notnull, dflt_value, pk
columns = {}
for row in self.cursor.fetchall():
logger.debug('Found table column: %s, %s' % (tableName, row))
typeName = row[2].lower()
# INTEGER PRIMARY KEY fields are auto-generated in sqlite
# INT PRIMARY KEY is not the same as INTEGER PRIMARY KEY!
autoincrement = bool(typeName == 'integer' and row[5])
if 'int' in typeName or 'bool' in typeName: # booleans are sotred as ints in sqlite
typeName = 'int'
elif typeName not in ('blob', 'text'):
raise TypeError('Unexpected data type: %s' % typeName)
column = Column(type = typeName, field = None, name = row[1], default = row[4],
precision = 19, nullable = (not row[3]), autoincrement = autoincrement)
columns[column.name] = column
logger.debug('Reproduced table column: %s, %s' % (tableName, column))
return columns
def checkTable(cls, db):
"""Check if corresponding table for this model exists in the db and has all necessary columns.
Add checkTable call in very model method that uses a db.
"""
assert isinstance(db, orm.GenericAdapter), 'Need a database adapter'
if db.uri in cls._checkedDbs: # this db was already checked
return
logger.debug('Model.checkTable: checking db table %s' % cls)
tableName = cls._name
if tableName not in db.getTables():
cls._handleTableMissing(db)
# import pprint
modelColumns = {field.column.name: field.column for field in cls}
dbColumns = db.getColumns(tableName)
# logger.debug(pprint.pformat(list(column.str() for column in dbColumns.values())))
# logger.debug(pprint.pformat(list(column.str() for column in modelColumns.values())))
for columnName, column in modelColumns.items():
dbColumn = dbColumns.pop(columnName, None)
if not dbColumn: # model column is not found in the db
print('Column in the db not found: %s' % column.str())
logger.debug('CREATE TABLE query:\n%s' % db.getCreateTableQuery(cls))
cls._checkedDbs.add(db.uri)
def get(cls, db, where, orderby = False, limit = False, select_related = False):
"""Get records from this table which fall under the given condition.
@param db: adapter to use
@param where: condition to filter
@param order: list of field to sort by
@param limit: tuple (from, to)
@param select_related: whether to retrieve objects related by foreign keys in the same query
"""
logger.debug("Model.get('%s', db= %s, where= %s, limit= %s)" % (cls, db, where, limit))
cls.checkTable(db)
orderby = orderby or cls._ordering # use default table ordering if no ordering passed
fields = list(cls)
from_ = [cls]
recordFields = []
if select_related:
for i, field in enumerate(cls):
if isinstance(field, orm.RecordField):
recordFields.append((i, field))
fields.extend(field.referTable)
from_.append(orm.LeftJoin(field.referTable, field == field.referTable.id))
#print(db._select(*fields, from_ = from_, where = where, orderby = orderby, limit = limit))
rows = db.select(*fields, from_ = from_, where = where, orderby = orderby, limit = limit)
for row in rows:
record = cls(db, *zip(cls, row))
if select_related:
fieldOffset = len(cls)
for i, recordField in recordFields:
referTable = recordField.referTable
if row[i] is None:
referRecord = None
else:
# if referRecord.id is None: # missing record !!! integrity error
referRecord = referTable(db, *zip(referTable, row[fieldOffset:]))
setattr(record, recordField.name, referRecord)
fieldOffset += len(referTable)
yield record
