refactor & add postgres

README.md

@@ -8,11 +8,11 @@
 
 **Quicker** is a pythonic tool for querying databases.
 
-Quicker wraps popular Python packages:
+Quicker wraps Python bindings on DBMS libraries:
 
 - `mysqlclient` for MySQL.
-- `psycopg2` for PostgreSQL (not implemented yet).
+- `psycopg2` for PostgreSQL.
-- Python builtin `sqlite` for SQLite (not implemented yet).
+- `sqlite` from Python standard library for SQLite (not implemented yet).
 
 Connection parameters will passed to "backend" module as is.
 
@@ -28,7 +28,7 @@ pip install git+https://git.nxhs.cloud/ge/quicker
 
 ```python
 with Connection(**config) as db:
-    db.exec("sql query here...")
+    db.execute("sql query here...")
     db.query("sql query here...")  # query is alias for exec()
 
 # Query is callable and you can also do this:
@@ -38,9 +38,10 @@ with Connection(**config) as query:
 
 `Query` cannot be called itself, you must use `Connection` to correctly initialise `Query` object. Available methods and properties:
 
-- `query()`, `exec()`. Execute SQL. There is You can use here this syntax: `query('SELECT * FROM users WHERE id = %s', (15,))`.
+- `query()`, `execute()`. Execute SQL. There is You can use here this syntax: `query('SELECT * FROM users WHERE id = %s', (15,))`.
 - `commit()`. Write changes into database.
-- `cursor`. Call [MySQLdb Cursor object](https://mysqlclient.readthedocs.io/user_guide.html#cursor-objects) methods directly.
+- `cursor`. Access cursor object directly.
+- `connection`. Access connection object directly.
 
 Full example:
 
@@ -88,7 +89,30 @@ Changing database:
 from quicker import Connection
 
 with Connection(provider='mysql', read_default_file='~/.my.cnf') as db:
-    db.query("INSERT INTO users VALUE (3, 'user2', 'user2@example.org')")
+    db.query("INSERT INTO `users` VALUE (3, 'user2', 'user2@example.org')")
 ```
 
 Quicker by default make commit after closing context. Set option `commit=False` to disable automatic commit.
+
+For logging add following code:
+
+```
+import logging
+
+logging.basicConfig(level=logging.DEBUG)
+```
+
+Direct access to Cursor object:
+
+```
+from quicker import Connection, make_list
+
+# config declaration here...
+
+with Connection(**config) as db:
+    db.cursor.execute('SELECT `id`, `name`, `email` FROM `users` WHERE `name` = %s', ('John',))
+    users = db.cursor.fetchall()
+    # Note: user is tuple! Convert it to list of dicts!
+    colnames = [desc[0] for desc in db.cursor.description]
+    users_list = make_list(colnames, users)
+```

TODO.todo

@@ -0,0 +1 @@
+Query должен возвращать либо список диктов, либо None, сейчас None не возвращает

docker-compose.yaml

@@ -2,7 +2,7 @@ version: '3.1'
 
 services:
 
-  db:
+  mysql:
     image: mysql:8
     command: --default-authentication-plugin=mysql_native_password
     restart: always
@@ -14,6 +14,16 @@ services:
     ports:
       - 3306:3306
 
+  postgres:
+    image: postgres:15
+    restart: always
+    environment:
+      POSTGRES_USER: myuser
+      POSTGRES_PASSWORD: example
+      POSTGRES_DB: mydb
+    ports:
+      - 5432:5432
+
   adminer:
     image: adminer
     restart: always

poetry.lock

@@ -1,23 +1,7 @@
 # This file is automatically @generated by Poetry 1.4.2 and should not be changed by hand.
-
+package = []
-[[package]]
-name = "mysqlclient"
-version = "2.2.0"
-description = "Python interface to MySQL"
-category = "main"
-optional = false
-python-versions = ">=3.8"
-files = [
-    {file = "mysqlclient-2.2.0-cp310-cp310-win_amd64.whl", hash = "sha256:68837b6bb23170acffb43ae411e47533a560b6360c06dac39aa55700972c93b2"},
-    {file = "mysqlclient-2.2.0-cp311-cp311-win_amd64.whl", hash = "sha256:5670679ff1be1cc3fef0fa81bf39f0cd70605ba121141050f02743eb878ac114"},
-    {file = "mysqlclient-2.2.0-cp38-cp38-win_amd64.whl", hash = "sha256:004fe1d30d2c2ff8072f8ea513bcec235fd9b896f70dad369461d0ad7e570e98"},
-    {file = "mysqlclient-2.2.0-cp39-cp39-win_amd64.whl", hash = "sha256:9c6b142836c7dba4f723bf9c93cc46b6e5081d65b2af807f400dda9eb85a16d0"},
-    {file = "mysqlclient-2.2.0-pp38-pypy38_pp73-win_amd64.whl", hash = "sha256:955dba905a7443ce4788c63fdb9f8d688316260cf60b20ff51ac3b1c77616ede"},
-    {file = "mysqlclient-2.2.0-pp39-pypy39_pp73-win_amd64.whl", hash = "sha256:530ece9995a36cadb6211b9787f0c9e05cdab6702549bdb4236af5e9b535ed6a"},
-    {file = "mysqlclient-2.2.0.tar.gz", hash = "sha256:04368445f9c487d8abb7a878e3d23e923e6072c04a6c320f9e0dc8a82efba14e"},
-]
 
 [metadata]
 lock-version = "2.0"
-python-versions = "^3.11"
+python-versions = "^3.8"
-content-hash = "462894cf2fdfd3121ca0c3a328dce7012ba1cecd25ba04d8a853c1fc21dde8a3"
+content-hash = "935b488be9f11b23f14aa1ce3bed4013d88bd77462534b5e4fe5bb82b485bfe9"

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "quicker"
-version = "0.1.0"
+version = "0.2.0"
 description = "Query databases quickly."
 authors = ["ge <ge@nixhacks.net>"]
 license = "Unlicense"
@@ -8,7 +8,6 @@ readme = "README.md"
 
 [tool.poetry.dependencies]
 python = "^3.8"
-mysqlclient = "^1.4.6"
 
 [build-system]
 requires = ["poetry-core"]

quicker/__init__.py

@@ -1 +1,9 @@
-from .main import Connection
+#    ____        _      __
+#   / __ \__  __(_)____/ /_____  _____
+#  / / / / / / / / ___/ //_/ _ \/ ___/
+# / /_/ / /_/ / / /__/ ,< /  __/ /
+# \___\_\__,_/_/\___/_/|_|\___/_/
+#
+# Quicker -- pythonic tool for querying databases
+
+from .main import Connection, make_list

quicker/main.py

@@ -1,5 +1,40 @@
+import logging
 import importlib.util
 from enum import Enum
+from typing import Optional, List, Union, Tuple
+
+
+logger = logging.getLogger(__name__)
+
+
+def _import(module_name: str, symbol: Optional[str] = None):
+    spec = importlib.util.find_spec(module_name)
+    if spec is None:
+        raise ImportError(f"Module '{module_name}' not found.")
+    module = importlib.util.module_from_spec(spec)
+    spec.loader.exec_module(module)
+    if symbol:
+        try:
+            return getattr(module, symbol)
+        except AttributeError:
+            raise ImportError()
+    return module
+
+
+def make_list(
+    column_names: List[str], rows: Union[tuple, Tuple[dict, ...]]
+) -> List[dict]:
+    """Convert output to list of dicts from tuples."""
+    data = []
+    for row in rows:
+        if isinstance(row, dict):
+            data.append(row)
+        else:
+            item  = {}
+            for i in range(len(row)):
+                item[column_names[i]] = row[i]
+            data.append(item)
+    return data
 
 
 class Provider(str, Enum):
@@ -12,7 +47,12 @@ class Provider(str, Enum):
 class Connection:
     """
     Connection is context manager that allows to establish connection
-    with database.
+    with database and make queries. Example::
+
+    >>> from quicker import Connection
+    >>> with Connection(provider='mysql', read_default_file='~/.my.cnf') as q:
+    ...     server = q('SELECT * FROM `servers` WHERE `id` = %s', (1735781,))
+    >>>
     """
 
     def __init__(self,
@@ -22,64 +62,90 @@ class Connection:
     ):
         if not provider:
             raise ValueError('Database provider is not set')
-        self._provider = provider
+        self._provider = Provider(provider)
         self._commit = commit
         self._connection_args = kwargs
 
     def __enter__(self):
+        logger.debug(f'Database provider={self._provider}')
+        # -- MySQL / MariaDB --
         if self._provider == Provider.MYSQL:
-            MySQLdb = self._import('MySQLdb')
+            MySQLdb = _import('MySQLdb')
-            self._connection = MySQLdb.connect(**self._connection_args)
+            DictCursor = _import('MySQLdb.cursors', 'DictCursor')
+            try:
+                if self._connection_args['cursorclass']:
+                    cursorclass = DictCursor
+            except KeyError:
+                cursorclass = DictCursor
+            self._connection = MySQLdb.connect(
+                **self._connection_args,
+                cursorclass=cursorclass,
+            )
+            logger.debug('Session started')
+            self._cursor = self._connection.cursor()
+            return Query(self)
+        # -- PostgreSQL --
+        if self._provider == Provider.POSTGRES:
+            psycopg2 = _import('psycopg2')
+            dbname = self._connection_args.pop('database')
+            self._connection_args['dbname'] = dbname
+            self._connection = psycopg2.connect(**self._connection_args)
             self._cursor = self._connection.cursor()
             return Query(self)
 
     def __exit__(self, exception_type, exception_value, exception_traceback):
-        if self._provider == Provider.MYSQL:
         if self._commit:
             self._connection.commit()
+            logger.debug('Changes commited into database')
         self._cursor.close()
         self._connection.close()
-
+        logger.debug('Connection closed')
-    def _import(self, lib: str):
-        spec = importlib.util.find_spec(lib)
-        if spec is None:
-            raise ImportError(f"Module '{lib}' not found.")
-        module = importlib.util.module_from_spec(spec)
-        spec.loader.exec_module(module)
-        return module
 
 
 class Query:
     def __init__(self, connect):
         self._provider = connect._provider
         self._connection = connect._connection
-        self.cursor = self._connection.cursor()
+        self._cursor = connect._cursor
 
     def __call__(self, *args, **kwargs):
-        return self.exec(*args, **kwargs)
+        return self.execute(*args, **kwargs)
 
     def query(self, *args, **kwargs):
-        return self.exec(*args, **kwargs)
+        return self.execute(*args, **kwargs)
 
-    def exec(self, *args, **kwargs):
+    def execute(self, *args, **kwargs) -> Union[List[dict], None]:
-        """Execute SQL query and return output if available."""
+        """Execute SQL query and return list of dicts or None."""
-        self.cursor.execute(*args, **kwargs)
-        self._fetchall = self.cursor.fetchall()
-        if self._fetchall is not None:
-            if self.cursor.description is not None:
-                self._field_names = [i[0] for i in self.cursor.description]
-            return self._conv(self._field_names, self._fetchall)
-
-    def commit(self):
-        """Commit changes into database."""
         if self._provider == Provider.MYSQL:
-            self._connection.commit()
+            self._cursor.execute(*args, **kwargs)
+            logger.debug(f'MySQLdb ran: {self._cursor._executed}')
+            self._fetchall = self._cursor.fetchall()
+        if self._provider == Provider.POSTGRES:
+            pgProgrammingError = _import('psycopg2', 'ProgrammingError')
+            self._cursor.execute(*args, **kwargs)
+            logger.debug(f'psycopg2 ran: {self._cursor.query}')
+            try:
+                self._fetchall = self._cursor.fetchall()
+            except pgProgrammingError as e:
+                self._fetchall = None
+        if self._fetchall is not None:
+            self._colnames = []
+            if self._cursor.description is not None:
+                self._colnames = [
+                    desc[0] for desc in self._cursor.description
+                ]
+            return make_list(self._colnames, self._fetchall)
+        return None
 
-    def _conv(self, field_names, rows) -> list[dict]:
+    def commit(self) -> None:
-        data = []
+        """Commit changes into database."""
-        for row in rows:
+        self._connection.commit()
-            item  = {}
+        logger.debug('Changes commited into database')
-            for i in range(len(row)):
+
-                item[field_names[i]] = row[i]
+    @property
-            data.append(item)
+    def connection(self):
-        return data
+        return self._connection
+
+    @property
+    def cursor(self):
+        return self._cursor