def __show_interface(self, database: Database) -> bool:
"""
Function shows a command line for this app.
On receiving a command from user, it passes query to Database entity, which tries to proceed it.
If Database got an Error, function prints this error.
In other case, it prints a result.
On \\q command from user, it simply returns False.
:param database: Database
:return: bool
"""
command = input(self.__present_command_line(database.get_name()))
if command == '\q':
return False
database.proceed_query(command)
if database.has_error():
print(database.get_error())
return True
if database.get_query().get_aggregate_function() != '':
print(database.get_query().get_result()[0])
else:
for row in database.get_query().get_result():
join_str = ', '
print(join_str.join(row))
return True
def test_database_default(self):
query = Query()
database = Database('database_name', query)
self.assertEqual(database.get_name(), 'database_name')
self.assertEqual(database.get_tables(), {})
self.assertEqual(database.get_error(), '')
self.assertEqual(database.has_error(), False)
self.assertEqual(database.get_query(), query)
def test_database_setters(self):
query = Query()
query.set_table('tada')
table = Table('table_name', [])
error_text = 'some error'
database = Database('database_name', query)
database.add_table(table)
database.set_error(error_text)
self.assertEqual(database.get_name(), 'database_name')
self.assertEqual(database.get_tables(), {'table_name': table})
self.assertEqual(database.get_error(), error_text)
self.assertEqual(database.has_error(), True)
self.assertEqual(database.get_query(), query)
def test_it_fails_if_field_not_exist(self):
query = Query()
table = Table('drivers', [[
'id', 'first_name', 'last_name', 'country', 'year_of_birth',
'company'
], ['1', 'John', 'Carmack', 'USA', '1970', 'id Software'
], ['2', 'Jonn', 'Romero', 'USA', '1967', 'id Software'
], ['3', 'Elon', 'Musk', 'USA', '1971', 'Tesla'
], ['4', 'Damon', 'Hill', 'UK', '1960', 'Williams']])
database = Database('database_name', query)
database.add_table(table)
database.proceed_query('SELECT *, id_name FROM drivers;')
self.assertEqual(database.get_query().get_select_expression(), [])
self.assertEqual(database.get_error(), 'Field not exist')
def test_it_parses_simple_where_statement_with_non_existed_field(self):
query = Query()
table = Table('drivers', [[
'id', 'first_name', 'last_name', 'country', 'year_of_birth',
'company'
], ['1', 'John', 'Carmack', 'USA', '1970', 'id Software'
], ['2', 'Jonn', 'Romero', 'USA', '1967', 'id Software'
], ['3', 'Elon', 'Musk', 'USA', '1971', 'Tesla'
], ['4', 'Damon', 'Hill', 'UK', '1960', 'Williams']])
database = Database('database_name', query)
database.add_table(table)
database.proceed_query(
"SELECT first_name FROM drivers WHERE if1 = 'USA';")
self.assertEqual(database.get_error(),
'Column from where_expression not found')
def test_it_shows_error_if_aggregate_function_witout_if_statement(self):
query = Query()
table = Table('drivers', [[
'id', 'first_name', 'last_name', 'country', 'year_of_birth',
'company'
], ['1', 'John', 'Carmack', 'USA', '1970', 'id Software'
], ['2', 'Jonn', 'Romero', 'USA', '1967', 'id Software'
], ['3', 'Elon', 'Musk', 'USA', '1971', 'Tesla'
], ['4', 'Damon', 'Hill', 'UK', '1960', 'Williams']])
database = Database('database_name', query)
database.add_table(table)
database.proceed_query('SELECT COUNT(*) FROM drivers;')
self.assertEqual(database.get_query().get_select_expression(), [])
self.assertEqual(
database.get_error(),
'Query contains aggregate function, but WHERE statement missed')
def test_database_proceed_filled_query_string_with_table_not_exist(self):
query = Query()
database = Database('database_name', query)
database.add_table(Table('drivers', []))
database.proceed_query('SELECT company, country FROM drivers1;')
self.assertEqual(database.get_error(), 'Table not exist')
def test_database_proceed_empty_query_string(self):
query = Query()
database = Database('database_name', query)
database.proceed_query('')
self.assertEqual(database.get_error(),
'Wrong query syntax, please try again')
