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 select_rows(self, query: Query) -> list:
selected = []
keys = self.__get_keys(query.get_select_expression())
for row in self.__rows:
formed_row = []
if self.__is_satisfied_by_where_clause(row,
query.get_where_clause()):
if query.get_aggregate_function() != '':
if query.get_aggregate_function() == 'COUNT(*)':
formed_row = row
else:
for key in keys:
formed_row.append(row[key])
selected.append(formed_row)
if query.get_aggregate_function() != '':
return [len(selected)]
return selected
def test_it_parses_simple_where_statement_with_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 country = 'USA';")
self.assertEqual(database.get_query().get_where_clause(),
[('', 'country', 'USA')])
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_it_parses_complicated_where_statement_with_second_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 country = 'USA' AND df = 'sdf';"
)
self.assertEqual(database.get_error(),
'Column from where_expression not found')
def test_query_setters(self):
query = Query()
query.set_select_expression(['country', 'first_name']),
query.set_aggregate_function('COUNT(*)'),
query.set_table('table_name'),
query.add_where_clause('', 'country', 'USA'),
query.set_result([3]),
self.assertEqual(query.get_select_expression(), ['country', 'first_name'])
self.assertEqual(query.get_aggregate_function(), 'COUNT(*)')
self.assertEqual(query.get_table(), 'table_name')
self.assertEqual(query.get_where_clause(), [('', 'country', 'USA')])
self.assertEqual(query.get_result(), [3])
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')