Add oracle lib

Based on mylib.pgsql.PgDB exiting lib and cx_Oracle, 
mylib.oracle.OracleDB provide an easy way to execute simple SQL query on 
an Oracle Database server.
This commit is contained in:
Benjamin Renard 2021-11-07 22:00:21 +01:00
parent dec88f814e
commit 7b1019cb1b
3 changed files with 796 additions and 0 deletions

361
mylib/oracle.py Normal file
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@ -0,0 +1,361 @@
# -*- coding: utf-8 -*-
""" Oracle client """
import logging
import sys
import cx_Oracle
log = logging.getLogger(__name__)
#
# Exceptions
#
class OracleDBException(Exception):
""" That is the base exception class for all the other exceptions provided by this module. """
def __init__(self, error, *args, **kwargs):
for arg, value in kwargs.items():
setattr(self, arg, value)
super().__init__(error.format(*args, **kwargs))
class OracleDBDuplicatedSQLParameter(OracleDBException, KeyError):
"""
Raised when trying to set a SQL query parameter
and an other parameter with the same name is already set
"""
def __init__(self, parameter_name):
super().__init__(
"Duplicated SQL parameter '{parameter_name}'",
parameter_name=parameter_name
)
class OracleDBUnsupportedWHEREClauses(OracleDBException, TypeError):
"""
Raised when trying to execute query with unsupported
WHERE clauses provided
"""
def __init__(self, where_clauses):
super().__init__(
"Unsupported WHERE clauses: {where_clauses}",
where_clauses=where_clauses
)
class OracleDB:
""" Oracle client """
def __init__(self, dsn, user, pwd, just_try=False):
self._dsn = dsn
self._user = user
self._pwd = pwd
self._conn = None
self.just_try = just_try
def connect(self):
""" Connect to Oracle server """
if self._conn is None:
try:
self._conn = cx_Oracle.connect(
user=self._user,
password=self._pwd,
dsn=self._dsn
)
except Exception:
log.fatal(
'An error occured during Oracle database connection (%s@%s).',
self._user, self._dsn, exc_info=1
)
sys.exit(1)
return True
def close(self):
""" Close connection with Oracle server (if opened) """
if self._conn:
self._conn.close()
self._conn = None
def doSQL(self, sql, params=None):
"""
Run SQL query and commit changes (rollback on error)
:param sql: The SQL query
:param params: The SQL query's parameters as dict (optional)
:return: True on success, False otherwise
:rtype: bool
"""
if self.just_try:
log.debug("Just-try mode : do not really execute SQL query '%s'", sql)
return True
cursor = self._conn.cursor()
try:
if isinstance(params, dict):
cursor.execute(sql, **params)
else:
cursor.execute(sql)
self._conn.commit()
return True
except Exception:
log.error(
'Error during SQL request "%s" %s',
sql,
"with params = %s" % ', '.join([
"%s = %s" % (key, value)
for key, value in params.items()
]) if params else "without params",
exc_info=True
)
self._conn.rollback()
return False
def doSelect(self, sql, params=None):
"""
Run SELECT SQL query and return list of selected rows as dict
:param sql: The SQL query
:param params: The SQL query's parameters as dict (optional)
:return: List of selected rows as dict on success, False otherwise
:rtype: list, bool
"""
cursor = self._conn.cursor()
try:
if isinstance(params, dict):
cursor.execute(sql, **params)
else:
cursor.execute(sql)
cursor.rowfactory = lambda *args: dict(zip([d[0] for d in cursor.description], args))
results = cursor.fetchall()
return results
except Exception:
log.error(
'Error during SQL request "%s" %s',
sql,
"with params = %s" % ', '.join([
"%s = %s" % (key, value)
for key, value in params.items()
]) if params else "without params",
exc_info=True
)
return False
#
# SQL helpers
#
@classmethod
def _combine_params(cls, params, to_add=None, **kwargs):
if to_add:
assert isinstance(to_add, dict), "to_add must be a dict or None"
params = cls._combine_params(params, **to_add)
for param, value in kwargs.items():
if param in params:
raise OracleDBDuplicatedSQLParameter(param)
params[param] = value
return params
@classmethod
def _format_where_clauses(cls, where_clauses, params=None, where_op=None):
"""
Format WHERE clauses
:param where_clauses: The WHERE clauses. Could be:
- a raw SQL WHERE clause as string
- a tuple of two elements: a raw WHERE clause and its parameters as dict
- a dict of WHERE clauses with field name as key and WHERE clause value as value
- a list of any of previous valid WHERE clauses
:param params: Dict of other already set SQL query parameters (optional)
:param where_op: SQL operator used to combine WHERE clauses together (optional, default: AND)
:return: A tuple of two elements: raw SQL WHERE combined clauses and parameters on success
:rtype: string, bool
"""
if params is None:
params = dict()
if where_op is None:
where_op = 'AND'
if isinstance(where_clauses, str):
return (where_clauses, params)
if isinstance(where_clauses, tuple) and len(where_clauses) == 2 and isinstance(where_clauses[1], dict):
cls._combine_params(params, where_clauses[1])
return (where_clauses[0], params)
if isinstance(where_clauses, (list, tuple)):
sql_where_clauses = []
for where_clause in where_clauses:
sql2, params = cls._format_where_clauses(where_clause, params=params, where_op=where_op)
sql_where_clauses.append(sql2)
return (
(" %s " % where_op).join(sql_where_clauses),
params
)
if isinstance(where_clauses, dict):
sql_where_clauses = []
for field, value in where_clauses.items():
param = field
if field in params:
idx = 1
while param in params:
param = '%s_%d' % (field, idx)
idx += 1
cls._combine_params(params, {param: value})
sql_where_clauses.append(
'"{field}" = :{param}'.format(field=field, param=param)
)
return (
(" %s " % where_op).join(sql_where_clauses),
params
)
raise OracleDBUnsupportedWHEREClauses(where_clauses)
@classmethod
def _add_where_clauses(cls, sql, params, where_clauses, where_op=None):
"""
Add WHERE clauses to an SQL query
:param sql: The SQL query to complete
:param params: The dict of parameters of the SQL query to complete
:param where_clauses: The WHERE clause (see _format_where_clauses())
:param where_op: SQL operator used to combine WHERE clauses together (optional, default: see _format_where_clauses())
:return:
:rtype: A tuple of two elements: raw SQL WHERE combined clauses and parameters
"""
if where_clauses:
sql_where, params = cls._format_where_clauses(where_clauses, params=params, where_op=where_op)
sql += " WHERE " + sql_where
return (sql, params)
@staticmethod
def _quote_table_name(table):
""" Quote table name """
return '"{0}"'.format(
'"."'.join(
table.split('.')
)
)
def insert(self, table, values, just_try=False):
""" Run INSERT SQL query """
sql = 'INSERT INTO {0} ("{1}") VALUES ({2})'.format(
self._quote_table_name(table),
'", "'.join(values.keys()),
", ".join([
':{0}'.format(key)
for key in values
])
)
if just_try:
log.debug("Just-try mode: execute INSERT query: %s", sql)
return True
log.debug(sql)
if not self.doSQL(sql, params=values):
log.error("Fail to execute INSERT query (SQL: %s)", sql)
return False
return True
def update(self, table, values, where_clauses, where_op=None, just_try=False):
""" Run UPDATE SQL query """
sql = 'UPDATE {0} SET {1}'.format(
self._quote_table_name(table),
", ".join([
'"{0}" = :{0}'.format(key)
for key in values
])
)
params = values
try:
sql, params = self._add_where_clauses(sql, params, where_clauses, where_op=where_op)
except (OracleDBDuplicatedSQLParameter, OracleDBUnsupportedWHEREClauses):
log.error('Fail to add WHERE clauses', exc_info=True)
return False
if just_try:
log.debug("Just-try mode: execute UPDATE query: %s", sql)
return True
log.debug(sql)
if not self.doSQL(sql, params=params):
log.error("Fail to execute UPDATE query (SQL: %s)", sql)
return False
return True
def delete(self, table, where_clauses, where_op='AND', just_try=False):
""" Run DELETE SQL query """
sql = 'DELETE FROM {0}'.format(self._quote_table_name(table))
params = dict()
try:
sql, params = self._add_where_clauses(sql, params, where_clauses, where_op=where_op)
except (OracleDBDuplicatedSQLParameter, OracleDBUnsupportedWHEREClauses):
log.error('Fail to add WHERE clauses', exc_info=True)
return False
if just_try:
log.debug("Just-try mode: execute UPDATE query: %s", sql)
return True
log.debug(sql)
if not self.doSQL(sql, params=params):
log.error("Fail to execute UPDATE query (SQL: %s)", sql)
return False
return True
def truncate(self, table, just_try=False):
""" Run TRUNCATE SQL query """
sql = 'TRUNCATE {0}'.format(self._quote_table_name(table))
if just_try:
log.debug("Just-try mode: execute TRUNCATE query: %s", sql)
return True
log.debug(sql)
if not self.doSQL(sql):
log.error("Fail to execute TRUNCATE query (SQL: %s)", sql)
return False
return True
def select(self, table, where_clauses=None, fields=None, where_op='AND', order_by=None, just_try=False):
""" Run SELECT SQL query """
sql = "SELECT "
if fields is None:
sql += "*"
elif isinstance(fields, str):
sql += '"{0}"'.format(fields)
else:
sql += '"{0}"'.format('", "'.join(fields))
sql += ' FROM {0}'.format(self._quote_table_name(table))
params = dict()
try:
sql, params = self._add_where_clauses(sql, params, where_clauses, where_op=where_op)
except (OracleDBDuplicatedSQLParameter, OracleDBUnsupportedWHEREClauses):
log.error('Fail to add WHERE clauses', exc_info=True)
return False
if order_by:
sql += ' ORDER BY {0}'.format(order_by)
if just_try:
log.debug("Just-try mode: execute SELECT query : %s", sql)
return just_try
return self.doSelect(sql, params=params)

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@ -45,6 +45,9 @@ setup(
'pgsql': [
'psycopg2',
],
'oracle': [
'cx_Oracle',
],
'mysql': [
'mysqlclient',
],

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tests/test_oracle.py Normal file
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# pylint: disable=redefined-outer-name,missing-function-docstring,protected-access
""" Tests on opening hours helpers """
import pytest
from mylib.oracle import OracleDB
class FakeCXOracleCursor:
""" Fake cx_Oracle cursor """
def __init__(self, expected_sql, expected_params, expected_return, expected_just_try, expected_exception):
self.expected_sql = expected_sql
self.expected_params = expected_params
self.expected_return = expected_return
self.expected_just_try = expected_just_try
self.expected_exception = expected_exception
def execute(self, sql, **params):
if self.expected_exception:
raise Exception("%s.execute(%s, %s): expected exception" % (self, sql, params))
if self.expected_just_try and not sql.lower().startswith('select '):
assert False, "%s.execute(%s, %s) may not be executed in just try mode" % (self, sql, params)
assert sql == self.expected_sql, "%s.execute(): Invalid SQL query:\n '%s'\nMay be:\n '%s'" % (self, sql, self.expected_sql)
assert params == self.expected_params, "%s.execute(): Invalid params:\n %s\nMay be:\n %s" % (self, params, self.expected_params)
return self.expected_return
def fetchall(self):
return self.expected_return
def __repr__(self):
return "FakeCXOracleCursor(%s, %s, %s, %s)" % (
self.expected_sql, self.expected_params,
self.expected_return, self.expected_just_try
)
class FakeCXOracle:
""" Fake cx_Oracle connection """
expected_sql = None
expected_params = dict()
expected_return = True
expected_just_try = False
expected_exception = False
just_try = False
def __init__(self, **kwargs):
allowed_kwargs = dict(dsn=str, user=str, password=(str, None))
for arg, value in kwargs.items():
assert arg in allowed_kwargs, "Invalid arg %s='%s'" % (arg, value)
assert isinstance(value, allowed_kwargs[arg]), "Arg %s not a %s (%s)" % (arg, allowed_kwargs[arg], type(value))
setattr(self, arg, value)
def close(self):
return self.expected_return
def cursor(self):
return FakeCXOracleCursor(
self.expected_sql, self.expected_params,
self.expected_return, self.expected_just_try or self.just_try,
self.expected_exception
)
def commit(self):
self._check_just_try()
return self.expected_return
def rollback(self):
self._check_just_try()
return self.expected_return
def _check_just_try(self):
if self.just_try:
assert False, "May not be executed in just try mode"
def fake_cxoracle_connect(**kwargs):
return FakeCXOracle(**kwargs)
def fake_cxoracle_connect_just_try(**kwargs):
con = FakeCXOracle(**kwargs)
con.just_try = True
return con
@pytest.fixture
def test_oracledb():
return OracleDB('127.0.0.1/dbname', 'user', 'password')
@pytest.fixture
def fake_oracledb(mocker):
mocker.patch('cx_Oracle.connect', fake_cxoracle_connect)
return OracleDB('127.0.0.1/dbname', 'user', 'password')
@pytest.fixture
def fake_just_try_oracledb(mocker):
mocker.patch('cx_Oracle.connect', fake_cxoracle_connect_just_try)
return OracleDB('127.0.0.1/dbname', 'user', 'password', just_try=True)
@pytest.fixture
def fake_connected_oracledb(fake_oracledb):
fake_oracledb.connect()
return fake_oracledb
@pytest.fixture
def fake_connected_just_try_oracledb(fake_just_try_oracledb):
fake_just_try_oracledb.connect()
return fake_just_try_oracledb
def generate_mock_args(expected_args=(), expected_kwargs=dict(), expected_return=True): # pylint: disable=dangerous-default-value
def mock_args(*args, **kwargs):
assert args == expected_args, "Invalid call args:\n %s\nMay be:\n %s" % (args, expected_args)
assert kwargs == expected_kwargs, "Invalid call kwargs:\n %s\nMay be:\n %s" % (kwargs, expected_kwargs)
return expected_return
return mock_args
def mock_doSQL_just_try(self, sql, params=None): # pylint: disable=unused-argument
assert False, "doSQL() may not be executed in just try mode"
def generate_mock_doSQL(expected_sql, expected_params=dict(), expected_return=True): # pylint: disable=dangerous-default-value
def mock_doSQL(self, sql, params=None): # pylint: disable=unused-argument
assert sql == expected_sql, "Invalid generated SQL query:\n '%s'\nMay be:\n '%s'" % (sql, expected_sql)
assert params == expected_params, "Invalid generated params:\n %s\nMay be:\n %s" % (params, expected_params)
return expected_return
return mock_doSQL
# OracleDB.doSelect() have same expected parameters as OracleDB.doSQL()
generate_mock_doSelect = generate_mock_doSQL
mock_doSelect_just_try = mock_doSQL_just_try
#
# Test on OracleDB helper methods
#
def test_combine_params_with_to_add_parameter():
assert OracleDB._combine_params(dict(test1=1), dict(test2=2)) == dict(
test1=1, test2=2
)
def test_combine_params_with_kargs():
assert OracleDB._combine_params(dict(test1=1), test2=2) == dict(
test1=1, test2=2
)
def test_combine_params_with_kargs_and_to_add_parameter():
assert OracleDB._combine_params(dict(test1=1), dict(test2=2), test3=3) == dict(
test1=1, test2=2, test3=3
)
def test_format_where_clauses_params_are_preserved():
args = ('test = test', dict(test1=1))
assert OracleDB._format_where_clauses(*args) == args
def test_format_where_clauses_raw():
assert OracleDB._format_where_clauses('test = test') == (('test = test'), dict())
def test_format_where_clauses_tuple_clause_with_params():
where_clauses = (
'test1 = :test1 AND test2 = :test2',
dict(test1=1, test2=2)
)
assert OracleDB._format_where_clauses(where_clauses) == where_clauses
def test_format_where_clauses_dict():
where_clauses = dict(test1=1, test2=2)
assert OracleDB._format_where_clauses(where_clauses) == (
'"test1" = :test1 AND "test2" = :test2',
where_clauses
)
def test_format_where_clauses_combined_types():
where_clauses = (
'test1 = 1',
('test2 LIKE :test2', dict(test2=2)),
dict(test3=3, test4=4)
)
assert OracleDB._format_where_clauses(where_clauses) == (
'test1 = 1 AND test2 LIKE :test2 AND "test3" = :test3 AND "test4" = :test4',
dict(test2=2, test3=3, test4=4)
)
def test_format_where_clauses_with_where_op():
where_clauses = dict(test1=1, test2=2)
assert OracleDB._format_where_clauses(where_clauses, where_op='OR') == (
'"test1" = :test1 OR "test2" = :test2',
where_clauses
)
def test_add_where_clauses():
sql = "SELECT * FROM table"
where_clauses = dict(test1=1, test2=2)
assert OracleDB._add_where_clauses(sql, None, where_clauses) == (
sql + ' WHERE "test1" = :test1 AND "test2" = :test2',
where_clauses
)
def test_add_where_clauses_preserved_params():
sql = "SELECT * FROM table"
where_clauses = dict(test1=1, test2=2)
params = dict(fake1=1)
assert OracleDB._add_where_clauses(sql, params.copy(), where_clauses) == (
sql + ' WHERE "test1" = :test1 AND "test2" = :test2',
dict(**where_clauses, **params)
)
def test_add_where_clauses_with_op():
sql = "SELECT * FROM table"
where_clauses = ('test1=1', 'test2=2')
assert OracleDB._add_where_clauses(sql, None, where_clauses, where_op='OR') == (
sql + ' WHERE test1=1 OR test2=2',
dict()
)
def test_add_where_clauses_with_duplicated_field():
sql = "UPDATE table SET test1=:test1"
params = dict(test1='new_value')
where_clauses = dict(test1='where_value')
assert OracleDB._add_where_clauses(sql, params, where_clauses) == (
sql + ' WHERE "test1" = :test1_1',
dict(test1='new_value', test1_1='where_value')
)
def test_quote_table_name():
assert OracleDB._quote_table_name("mytable") == '"mytable"'
assert OracleDB._quote_table_name("myschema.mytable") == '"myschema"."mytable"'
def test_insert(mocker, test_oracledb):
values = dict(test1=1, test2=2)
mocker.patch(
'mylib.oracle.OracleDB.doSQL',
generate_mock_doSQL(
'INSERT INTO "mytable" ("test1", "test2") VALUES (:test1, :test2)',
values
)
)
assert test_oracledb.insert('mytable', values)
def test_insert_just_try(mocker, test_oracledb):
mocker.patch('mylib.oracle.OracleDB.doSQL', mock_doSQL_just_try)
assert test_oracledb.insert('mytable', dict(test1=1, test2=2), just_try=True)
def test_update(mocker, test_oracledb):
values = dict(test1=1, test2=2)
where_clauses = dict(test3=3, test4=4)
mocker.patch(
'mylib.oracle.OracleDB.doSQL',
generate_mock_doSQL(
'UPDATE "mytable" SET "test1" = :test1, "test2" = :test2 WHERE "test3" = :test3 AND "test4" = :test4',
dict(**values, **where_clauses)
)
)
assert test_oracledb.update('mytable', values, where_clauses)
def test_update_just_try(mocker, test_oracledb):
mocker.patch('mylib.oracle.OracleDB.doSQL', mock_doSQL_just_try)
assert test_oracledb.update('mytable', dict(test1=1, test2=2), None, just_try=True)
def test_delete(mocker, test_oracledb):
where_clauses = dict(test1=1, test2=2)
mocker.patch(
'mylib.oracle.OracleDB.doSQL',
generate_mock_doSQL(
'DELETE FROM "mytable" WHERE "test1" = :test1 AND "test2" = :test2',
where_clauses
)
)
assert test_oracledb.delete('mytable', where_clauses)
def test_delete_just_try(mocker, test_oracledb):
mocker.patch('mylib.oracle.OracleDB.doSQL', mock_doSQL_just_try)
assert test_oracledb.delete('mytable', None, just_try=True)
def test_truncate(mocker, test_oracledb):
mocker.patch(
'mylib.oracle.OracleDB.doSQL',
generate_mock_doSQL('TRUNCATE "mytable"', None)
)
assert test_oracledb.truncate('mytable')
def test_truncate_just_try(mocker, test_oracledb):
mocker.patch('mylib.oracle.OracleDB.doSQL', mock_doSelect_just_try)
assert test_oracledb.truncate('mytable', just_try=True)
def test_select(mocker, test_oracledb):
fields = ('field1', 'field2')
where_clauses = dict(test3=3, test4=4)
expected_return = [
dict(field1=1, field2=2),
dict(field1=2, field2=3),
]
order_by = "field1, DESC"
mocker.patch(
'mylib.oracle.OracleDB.doSelect',
generate_mock_doSQL(
'SELECT "field1", "field2" FROM "mytable" WHERE "test3" = :test3 AND "test4" = :test4 ORDER BY ' + order_by,
where_clauses, expected_return
)
)
assert test_oracledb.select('mytable', where_clauses, fields, order_by=order_by) == expected_return
def test_select_without_field_and_order_by(mocker, test_oracledb):
mocker.patch(
'mylib.oracle.OracleDB.doSelect',
generate_mock_doSQL(
'SELECT * FROM "mytable"'
)
)
assert test_oracledb.select('mytable')
def test_select_just_try(mocker, test_oracledb):
mocker.patch('mylib.oracle.OracleDB.doSQL', mock_doSelect_just_try)
assert test_oracledb.select('mytable', None, None, just_try=True)
#
# Tests on main methods
#
def test_connect(mocker, test_oracledb):
expected_kwargs = dict(
dsn=test_oracledb._dsn,
user=test_oracledb._user,
password=test_oracledb._pwd
)
mocker.patch(
'cx_Oracle.connect',
generate_mock_args(
expected_kwargs=expected_kwargs
)
)
assert test_oracledb.connect()
def test_close(fake_oracledb):
assert fake_oracledb.close() is None
def test_close_connected(fake_connected_oracledb):
assert fake_connected_oracledb.close() is None
def test_doSQL(fake_connected_oracledb):
fake_connected_oracledb._conn.expected_sql = 'DELETE FROM table WHERE test1 = :test1'
fake_connected_oracledb._conn.expected_params = dict(test1=1)
fake_connected_oracledb.doSQL(fake_connected_oracledb._conn.expected_sql, fake_connected_oracledb._conn.expected_params)
def test_doSQL_without_params(fake_connected_oracledb):
fake_connected_oracledb._conn.expected_sql = 'DELETE FROM table'
fake_connected_oracledb.doSQL(fake_connected_oracledb._conn.expected_sql)
def test_doSQL_just_try(fake_connected_just_try_oracledb):
assert fake_connected_just_try_oracledb.doSQL('DELETE FROM table')
def test_doSQL_on_exception(fake_connected_oracledb):
fake_connected_oracledb._conn.expected_exception = True
assert fake_connected_oracledb.doSQL('DELETE FROM table') is False
def test_doSelect(fake_connected_oracledb):
fake_connected_oracledb._conn.expected_sql = 'SELECT * FROM table WHERE test1 = :test1'
fake_connected_oracledb._conn.expected_params = dict(test1=1)
fake_connected_oracledb._conn.expected_return = [dict(test1=1)]
assert fake_connected_oracledb.doSelect(
fake_connected_oracledb._conn.expected_sql,
fake_connected_oracledb._conn.expected_params) == fake_connected_oracledb._conn.expected_return
def test_doSelect_without_params(fake_connected_oracledb):
fake_connected_oracledb._conn.expected_sql = 'SELECT * FROM table'
fake_connected_oracledb._conn.expected_return = [dict(test1=1)]
assert fake_connected_oracledb.doSelect(fake_connected_oracledb._conn.expected_sql) == fake_connected_oracledb._conn.expected_return
def test_doSelect_on_exception(fake_connected_oracledb):
fake_connected_oracledb._conn.expected_exception = True
assert fake_connected_oracledb.doSelect('SELECT * FROM table') is False
def test_doSelect_just_try(fake_connected_just_try_oracledb):
fake_connected_just_try_oracledb._conn.expected_sql = 'SELECT * FROM table WHERE test1 = :test1'
fake_connected_just_try_oracledb._conn.expected_params = dict(test1=1)
fake_connected_just_try_oracledb._conn.expected_return = [dict(test1=1)]
assert fake_connected_just_try_oracledb.doSelect(
fake_connected_just_try_oracledb._conn.expected_sql,
fake_connected_just_try_oracledb._conn.expected_params
) == fake_connected_just_try_oracledb._conn.expected_return