def select(self, name: str, fields: list, is_star: bool, condition,
is_versioning, from_date, to_date):
if not self.is_table_exists(name):
return Result.Result(
True,
exception_for_client.DBExceptionForClient().TableNotExists(
name))
elif type(self.is_fields_exist(name, fields)) is str:
return Result.Result(
True,
exception_for_client.DBExceptionForClient().FieldNotExists(
self.is_fields_exist(name, fields)))
else:
table_index = self.get_table_index(name)
rows = []
fields = self.build_fields(fields, is_star, table_index)
index = self.get_index_for_select(name, fields)
if not (index) or not self.check_where_condition(
condition, fields):
for block in self.db.tables[table_index].iter_blocks():
for row in block.iter_rows():
if row.status == 1:
if self.solve_condition(condition, row):
rows.append(row)
else:
rows = self.get_rows_using_index(index, condition, table_index,
fields)
rows.sort(key=lambda x: x.index_in_file)
transaction_index = 0
user = self.get_user(self.current_user_index)
if user.is_transaction:
self.begin_table_transaction(table_index)
transaction_index = user.transactions[table_index]
if is_versioning:
from_date = datetime(from_date.year, from_date.month,
from_date.day, from_date.hour,
from_date.minute, from_date.second,
from_date.millisecond)
to_date = datetime(to_date.year, to_date.month, to_date.day,
to_date.hour, to_date.minute,
to_date.second, to_date.millisecond)
rows = self.db.tables[table_index].select(
fields, rows, transaction_index, from_date, to_date)
else:
rows = self.db.tables[table_index].select(
fields, rows, transaction_index)
for i in range(len(rows)):
rows[i] = Row(self.dict_to_list(rows[i].fields_values_dict))
return Table(fields, rows)
def union(self,
first_table: Table,
second_table: Table,
is_all=False) -> Table or Result.Result:
if len(first_table.fields) != len(second_table.fields):
return Result.Result(
True,
exception_for_client.DBExceptionForClient().
DifferentNumberOfColumns())
table = Table(first_table.fields, [])
if is_all:
for row in first_table.rows:
table.rows.append(row)
for row in second_table.rows:
table.rows.append(row)
else:
for first_row in first_table.rows:
is_unique = True
for row in table.rows:
if self.are_rows_equal([table.fields, first_row],
[table.fields, row]):
is_unique = False
if is_unique:
table.rows.append(first_row)
for second_row in second_table.rows:
is_unique = True
for row in table.rows:
if self.are_rows_equal([table.fields, second_row],
[table.fields, row]):
is_unique = False
if is_unique:
table.rows.append(second_row)
return table
def get_values(self, name: str, values: list,
fields=()) -> list or Result.Result:
types = self.get_types(name, values, fields)
if len(types) == 0:
return []
for i in range(len(values)):
if types[i].name == 'float':
try:
values[i] = float(values[i].name)
except:
return []
elif types[i].name == "int":
try:
values[i] = int(values[i].name)
except:
return []
elif types[i].name == "bool":
if values[i].name == "False":
values[i] = False
elif values[i].name == "True":
values[i] = True
else:
return []
elif types[i].name == "str":
if values[i].is_str:
values[i] = values[i].name
else:
return Result.Result(
True,
exception_for_client.DBExceptionForClient().
WrongFieldType(values[i].name))
else:
return []
return values
def delete(self, name: str, condition):
if not self.is_table_exists(name):
return Result.Result(
True,
exception_for_client.DBExceptionForClient().TableNotExists(
name))
else:
table_index = self.get_table_index(name)
if self.db.tables[table_index].is_locked:
if not self.current_user_index == self.locked_tables[
table_index]:
return Result.Result(True, "Table is locked")
rows_indices = []
for block in self.db.tables[table_index].iter_blocks():
for row in block.iter_rows():
if row.status == 1:
if self.solve_condition(condition, row):
rows_indices.append(row.index_in_file)
transaction_index = 0
user = self.get_user(self.current_user_index)
if user.is_transaction:
self.begin_table_transaction(table_index)
transaction_index = user.transactions[table_index]
self.db.tables[table_index].delete(rows_indices, transaction_index)
return Result.Result(False)
def solve_expression(self, root, row) -> int or Result.Result:
if root.getRootVal() == '+':
value = self.solve_expression(root.getLeftChild(),
row) + self.solve_expression(
root.getRightChild(), row)
elif root.getRootVal() == '-':
value = self.solve_expression(root.getLeftChild(),
row) - self.solve_expression(
root.getRightChild(), row)
elif root.getRootVal() == '*':
value = self.solve_expression(root.getLeftChild(),
row) * self.solve_expression(
root.getRightChild(), row)
elif root.getRootVal() == '/':
value = self.solve_expression(root.getLeftChild(),
row) / self.solve_expression(
root.getRightChild(), row)
else:
try:
value = float(root.getRootVal().name)
except:
if root.getRootVal().is_str:
value = row.fields_values_dict[root.getRootVal().name]
else:
if root.getRootVal().name in row.fields_values_dict:
value = row.fields_values_dict[root.getRootVal().name]
else:
return Result.Result(
True,
exception_for_client.DBExceptionForClient().
FieldNotExists(root.getRootVal().name))
return value
def drop_table(self, name: str) -> Result:
if not self.is_table_exists(name):
return Result.Result(
True,
exception_for_client.DBExceptionForClient().TableNotExists(
name))
else:
return Result.Result(False)
def update(self, name: str, fields: list, values: list, condition):
if not self.is_table_exists(name):
return Result.Result(
True,
exception_for_client.DBExceptionForClient().TableNotExists(
name))
elif type(self.is_fields_exist(name, fields)) is str:
return Result.Result(
True,
exception_for_client.DBExceptionForClient().FieldNotExists(
self.is_fields_exist(name, fields)))
else:
table_index = self.get_table_index(name)
if self.db.tables[table_index].is_locked:
if not self.current_user_index == self.locked_tables[
table_index]:
return Result.Result(True, "Table is locked")
rows = []
new_values = []
for block in self.db.tables[table_index].iter_blocks():
for row in block.iter_rows():
if row.status == 1:
if self.solve_condition(condition, row):
temp = self.get_values_with_expression(
name, values, row, fields)
if type(temp) == Result.Result:
return temp
if len(temp) == 0:
return Result.Result(
True,
exception_for_client.DBExceptionForClient(
).InvalidDataType())
new_values.append(temp)
rows.append(row)
for i in range(len(fields)):
fields[i] = fields[i].name
sorted(rows, key=lambda row: row.transaction_end)
transaction_index = 0
user = self.get_user(self.current_user_index)
if user.is_transaction:
self.begin_table_transaction(table_index)
transaction_index = user.transactions[table_index]
self.db.tables[table_index].update(fields, new_values, rows,
transaction_index)
return Result.Result(False)
def create_table(self,
name: str,
fields: list = (),
is_versioning: bool = False) -> Result:
correct_fields = self.get_correct_fields(fields)
if not (type(correct_fields) is dict):
return Result.Result(
True,
exception_for_client.DBExceptionForClient().DuplicateFields(
correct_fields))
elif self.is_table_exists(name):
return Result.Result(
True,
exception_for_client.DBExceptionForClient().TableAlreadyExists(
name))
else:
self.db.create_table(name, correct_fields, is_versioning)
return Result.Result(False)
def show_create_table(self, name: str) -> Result:
if not self.is_table_exists(name):
return Result.Result(
True,
exception_for_client.DBExceptionForClient().TableNotExists(
name))
else:
table_index = self.get_table_index(name)
return Result.Result(False,
self.db.tables[table_index].show_create())
def check_required_fields(left_table: Table, right_table: Table,
fields: list, left_table_name: str,
right_table_name: str) -> Result.Result:
for field in fields:
if field.type == "field":
return Result.Result(
True,
exception_for_client.DBExceptionForClient().
NoTableSpecified(field.name))
if not (field.name_table in [left_table_name, right_table_name]):
return Result.Result(
True,
exception_for_client.DBExceptionForClient().FieldNotExists(
field.name))
if not (field.name in left_table.fields) or not (
field.name in right_table.fields):
return Result.Result(
True,
exception_for_client.DBExceptionForClient().FieldNotExists(
field.name))
def show_index(self, table_name):
if not self.is_table_exists(table_name):
return Result.Result(
True,
exception_for_client.DBExceptionForClient().TableNotExists(
table_name))
str_for_print = "\n| index name | \n"
for index in self.indices:
if index.table_name == table_name:
str_for_print += "| " + index.index_name + " | \n"
return Result.Result(False, str_for_print)
def p_error(p):
if p == None:
pos = "Last symbol"
val = ""
else:
pos = p.lexpos
val = p.value
global result
result = Result.Result(
True,
exception_for_client.DBExceptionForClient().IncorrectSyntax(pos, val))
def drop_index(self, index_name, table_name):
if not self.is_table_exists(table_name):
return Result.Result(
True,
exception_for_client.DBExceptionForClient().TableNotExists(
table_name))
elif not self.is_index_exist(index_name, table_name):
return Result.Result(
True,
exception_for_client.DBExceptionForClient().IndexNotExists(
index_name))
index_id = self.get_index(index_name, table_name)
table_index = self.get_table_index(table_name)
self.db.tables[table_index].delete_index(index_id)
indices = []
for index in self.indices:
if not (index.index_name == index_name
and index.table_name == table_name):
indices.append(index)
self.indices = indices
return Result.Result(False, "")
def end_transaction(self, user_index):
user = self.pr.get_user(user_index)
if not user.is_transaction:
return Result.Result(
True,
exception_for_client.DBExceptionForClient().
TransactionNotDefined(user_index))
for table_index in user.transactions:
self.pr.db.tables[table_index].end_transaction(
user.transactions[table_index])
self.pr.db.tables[table_index].is_locked = False
user.transactions = {}
user.is_transaction = False
return Result.Result(False, "")
def insert(self, name: str, fields: list, values: list):
if not self.is_table_exists(name):
return Result.Result(
True,
exception_for_client.DBExceptionForClient().TableNotExists(
name))
elif type(self.is_fields_exist(name, fields)) is str:
return Result.Result(
True,
exception_for_client.DBExceptionForClient().FieldNotExists(
self.is_fields_exist(name, fields)))
else:
new_values = self.get_values(name, values, fields)
if type(new_values) is Result.Result:
return new_values
if not len(new_values):
return Result.Result(
True,
exception_for_client.DBExceptionForClient().
InvalidDataType())
table_index = self.get_table_index(name)
if self.db.tables[table_index].is_locked:
if not self.current_user_index == self.locked_tables[
table_index]:
return Result.Result(True, "Table is locked")
if len(fields) == 0:
for i in range(len(values)):
fields.append(self.db.tables[table_index].fields[i])
if len(new_values) != 0:
transaction_index = 0
user = self.get_user(self.current_user_index)
if user.is_transaction:
self.begin_table_transaction(table_index)
transaction_index = user.transactions[table_index]
self.db.tables[table_index].insert(fields, new_values, -1,
transaction_index)
return Result.Result(False)
def create_index(self, index_name, table_name, fields):
if not self.is_table_exists(table_name):
return Result.Result(
True,
exception_for_client.DBExceptionForClient().TableNotExists(
table_name))
elif type(self.is_fields_exist(table_name, fields)) is str:
return Result.Result(
True,
exception_for_client.DBExceptionForClient().FieldNotExists(
self.is_fields_exist(table_name, fields)))
elif self.is_index_exist(index_name, table_name):
return Result.Result(
True,
exception_for_client.DBExceptionForClient().IndexAlreadyExists(
index_name))
table_index = self.get_table_index(table_name)
fields_for_eng = []
for field in fields:
fields_for_eng.append(field.name)
index_id = self.db.tables[table_index].create_index(fields_for_eng)
self.indices.append(
Index(index_name, index_id, table_name, fields_for_eng))
return Result.Result(False, "")
def get_values_with_expression(self,
name: str,
values: list,
row,
fields=()) -> list or Result.Result:
types = self.get_types(name, values, fields)
if len(types) == 0:
return []
new_values = []
for i in range(len(values)):
if types[i].name == "float":
try:
new_values.append(
float(self.solve_expression(values[i], row)))
except:
return []
elif types[i].name == "int":
try:
new_values.append(
int(self.solve_expression(values[i], row)))
except:
return []
elif types[i].name == "bool":
if self.solve_expression(values[i], row) == "False":
new_values.append(False)
elif self.solve_expression(values[i], row) == "True":
new_values.append(True)
else:
return []
elif types[i].name == "str":
if values[i].type == "field":
if values[i].is_str:
new_values.append(values[i].name)
else:
return Result.Result(
True,
exception_for_client.DBExceptionForClient().
WrongFieldType(values[i].name))
else:
new_values.append(values[i].name)
else:
return []
return new_values