aiopyql 0.290

Simple python database orchestration utility which makes it easy to add tables, insert, select, update, delete items with tables

aioaiopyql

Asyncio ORM(Object-relational mapping) for accessing, inserting, updating, deleting data within RBDMS tables using python, based on the synchronus ORM pyql

Instalation

$ virtualenv -p python3.7 aiopyql-env

$ source aiopyql-env/bin/activate

Install with PIP

 (aiopyql-env)$ pip install aiopyql

Download & install Library from repo:

(aiopyql-env)$ git clone https://github.com/codemation/aiopyql.git

Use install script to install the aiopyql into the activated environment libraries

(aiopyql-env)$ cd aiopyql; sudo ./install.py install

Compatable Databases - Currently

• mysql
• sqlite

Getting Started

A Database object can be created both in and out of an event loop, but the Database.create() factory coro ensures load_tables() is processed to load existing tables.

DB connection

Sqlite3: Default

    from aiopyql import data
    import asyncio


    async def main():

        #sqlite connection
        sqlite_db = await data.Database.create(
            database="testdb" # if no type specified, default is sqlite
        )

        # mysql connection
        mysql_db = await data.Database.create(
            database='mysql_database',
            user='mysqluser',
            password='my-secret-pw',
            host='localhost',
            type='mysql'
            )

        # more db logic goes here

    loop = asyncio.new_event_loop()
    loop.run_until_complete(main())

Existing tables schemas within databases are loaded when database object is instantiated via .create and ready for use immedielty.

If created using db = data.Database(database='testdb'), which is synchronus, the .load_tables() coro must be run manually within an event loop or _run_async_tasks utility func

    # synchronus 
    db = data.Database(database='testdb')
    db._run_async_tasks(db.load_tables())

_run_async_tasks cannot be used within running event loop

Table Create

Requires List of at least 2 item tuples, max 3

('column_name', type, 'modifiers')

• column_name - str - database column name exclusions apply
• types: str, int, float, byte, bool, None # JSON dumpable dicts fall under str types
• modifiers: NOT NULL, UNIQUE, AUTO_INCREMENT

Note Some differences may apply for column options i.e AUTOINCREMENT(sqlite) vs AUTO_INCREMENT(mysql) - See DB documentation for reference.

Note: Unique constraints are not validated by aiopyql but at db, so if modifier is supported it will be added when table is created.

# Table Create    
await db.create_table(
    'stocks', 
    [    
        ('order_num', int, 'AUTO_INCREMENT'),
        ('date', str),
        ('trans', str),
        ('symbol', str),
        ('qty', float),
        ('price', str)
    ], 
    'order_num' # Primary Key 
)

mysql> describe stocks;
+-----------+---------+------+-----+---------+----------------+
| Field     | Type    | Null | Key | Default | Extra          |
+-----------+---------+------+-----+---------+----------------+
| order_num | int(11) | NO   | PRI | NULL    | auto_increment |
| date      | text    | YES  |     | NULL    |                |
| trans     | text    | YES  |     | NULL    |                |
| condition | text    | YES  |     | NULL    |                |
| symbol    | text    | YES  |     | NULL    |                |
| qty       | double  | YES  |     | NULL    |                |
| price     | text    | YES  |     | NULL    |                |
+-----------+---------+------+-----+---------+----------------+
6 rows in set (0.00 sec)

Creating Tables with Foreign Keys

await db.create_table(
    'departments', 
    [    
        ('id', int, 'UNIQUE'),
        ('name', str)
    ], 
    'id' # Primary Key 
)

await db.create_table(
    'positions', 
    [    
        ('id', int, 'UNIQUE'),
        ('name', str),
        ('department_id', int)
    ], 
    'id', # Primary Key
    foreign_keys={
        'department_id': {
            'table': 'departments', 
            'ref': 'id',
            'mods': 'ON UPDATE CASCADE ON DELETE CASCADE'
        }
    }
)

await db.create_table(
    'employees', 
    [    
        ('id', int, 'UNIQUE'),
        ('name', str),
        ('position_id', int)
    ], 
    'id', # Primary Key
    foreign_keys={
        'position_id': {
            'table': 'positions', 
            'ref': 'id',
            'mods': 'ON UPDATE CASCADE ON DELETE CASCADE'
        }
    }
)

Insert Data

Requires key-value pairs - may be input using dict or the following

Un-packing

# Note order_num is not required as auto_increment was specified
trade = {'date': '2006-01-05', 'trans': 'BUY', 'symbol': 'RHAT', 'qty': 100.0, 'price': 35.14}
await db.tables['stocks'].insert(**trade)

query:
    INSERT INTO stocks (date, trans, symbol, qty, price) VALUES ("2006-01-05", "BUY", "RHAT", 100, 35.14)

In-Line

# Note order_num is not required as auto_increment was specified
await db.tables['stocks'].insert(
    date='2006-01-05', 
    trans='BUY',
    symbol='RHAT',
    qty=200.0,
    price=65.14
)

query:
    INSERT INTO stocks (date, trans, symbol, qty, price) VALUES ("2006-01-05", "BUY", "RHAT", 200, 65.14)

Inserting Special Data

• Columns of type string can hold JSON dumpable python dictionaries as JSON strings and are automatically converted back into dicts when read.

• Nested Dicts are also Ok, but all items should be JSON compatible data types

    tx_data = {
        'type': 'BUY', 
        'condition': {
            'limit': '36.00', 
            'time': 'end_of_trading_day'
        }
    }
  
    trade = {
        'order_num': 1, 'date': '2006-01-05', 
        'trans': tx_data, # 
        'symbol': 'RHAT', 
        'qty': 100, 'price': 35.14, 'after_hours': True
    }
  
    await db.tables['stocks'].insert(**trade)
    query:
        INSERT INTO stocks 
            (
                order_num, 
                date, trans, 
                symbol, 
                qty, 
                price, 
                after_hours
            ) 
            VALUES 
                (
                    1, 
                    "2006-01-05", 
                    '{"type": "BUY", "condition": {"limit": "36.00", "time": "end_of_trading_day"}}', 
                    "RHAT", 
                    100, 
                    35.14, 
                    True
                )
    result:
        In:
            sel = await db.tables['stocks'][1]
            print(sel['trans']['condition'])
        Out: #
            {'limit': '36.00', 'time': 'end_of_trading_day'}
  

Select Data

Basic Usage:

All Rows & Columns in table

await db.tables['employees'].select('*')

All Rows & Specific Columns

await db.tables['employees'].select(
    'id', 
    'name', 
    'position_id'
    )

All Rows & Specific Columns with Matching Values

await db.tables['employees'].select(
    'id', 
    'name', 
    'position_id', 
    where={
        'id': 1000
        }
    )

All Rows & Specific Columns with Multple Matching Values

await db.tables['employees'].select(
    'id', 
    'name', 
    'position_id', 
    where={
        'id': 1000, 
        'name': 'Frank Franklin'}
    )

Advanced Usage:

All Rows & Columns from employees, Combining ALL Rows & Columns of table positions (if foreign keys match)

# Basic Join
await db.tables['employees'].select('*', join='positions')
query:
    SELECT * FROM employees JOIN positions ON employees.position_id = positions.id
output:
    [
        {
            'employees.id': 1000, 
            'employees.name': 'Frank Franklin', 
            'employees.position_id': 100101, 
            'positions.name': 'Director', 
            'positions.department_id': 1001
        },
        ...
    ]

All Rows & Specific Columns from employees, Combining All Rows & Specific Columns of table positions (if foreign keys match)

# Basic Join 
await db.tables['employees'].select(
    'employees.name', 
    'positions.name', 
    join='positions' # # possible only if foreign key relation exists between employees & positions
    )
query:
    SELECT employees.name,positions.name FROM employees JOIN positions ON employees.position_id = positions.id
output:
    [
        {'employees.name': 'Frank Franklin', 'positions.name': 'Director'}, 
        {'employees.name': 'Eli Doe', 'positions.name': 'Manager'},
        ...
    ]

All Rows & Specific Columns from employees, Combining All Rows & Specific Columns of table positions (if foreign keys match) with matching 'position.name' value

# Basic Join with conditions
await db.tables['employees'].select(
    'employees.name', 
    'positions.name', 
    join='positions', # possible only if foreign key relation exists between employees & positions
    where={
        'positions.name': 'Director'}
    )
query:
    SELECT 
        employees.name,
        positions.name 
    FROM 
        employees 
    JOIN positions 
        ON 
            employees.position_id = positions.id 
    WHERE 
        positions.name='Director'
output:
    [
        {'employees.name': 'Frank Franklin', 'positions.name': 'Director'}, 
        {'employees.name': 'Elly Doe', 'positions.name': 'Director'},
        ..
    ]

All Rows & Specific Columns from employees, Combining Specific Rows & Specific Columns of tables positions & departments

Note: join='x_table' will only work if the calling table has a f-key reference to table 'x_table'

# Multi-table Join with conditions
await db.tables['employees'].select(
    'employees.name', 
    'positions.name', 
    'departments.name', 
    join={
        'positions': {
            'employees.position_id': 'positions.id'
            }, 
        'departments': {
            'positions.department_id': 'departments.id'
            }
    }, 
    where={
        'positions.name': 'Director'}
    )
query:
    SELECT 
        employees.name,positions.name,
        departments.name 
    FROM 
        employees 
    JOIN 
        positions 
            ON 
                employees.position_id = positions.id 
    JOIN 
        departments 
            ON 
                positions.department_id = departments.id 
    WHERE 
        positions.name='Director'
result:
    [
        {'employees.name': 'Frank Franklin', 'positions.name': 'Director', 'departments.name': 'HR'}, 
        {'employees.name': 'Elly Doe', 'positions.name': 'Director', 'departments.name': 'Sales'}
    ]

Special Note: When performing multi-table joins, joining columns must be explicity provided. The key-value order is not explicity important, but will determine which column name is present in returned rows

join={'y_table': {'y_table.id': 'x_table.y_id'}}
result:
    [
        {'x_table.a': 'val1', 'y_table.id': 'val2'},
        {'x_table.a': 'val1', 'y_table.id': 'val3'}
    ]

OR

join={'y_table': {'x_table.y_id': 'y_table.id'}}
result:
    [
        {'x_table.a': 'val1', 'x_table.y_id': 'val2'},
        {'x_table.a': 'val1', 'x_table.y_id': 'val3'}
    ]

Special Examples:

Bracket indexs can only be used for primary keys and return entire row, if existent

await db.tables['employees'][1000] 

query:
    SELECT * 
    FROM 
        employees 
    WHERE 
        id=1000
result:
    {'id': 1000, 'name': 'Frank Franklin', 'position_id': 100101}

Note: As db.tables['employees'][1000] returns an 'awaitable', sub keys cannot be specified until the object has been 'awaited'

In: 
    # Wrong
    await db.tables['employees'][1000]['id']
Out:
    __main__:1: RuntimeWarning: coroutine was never awaited
    RuntimeWarning: Enable tracemalloc to get the object allocation traceback
    Traceback (most recent call last):
    File "<stdin>", line 1, in <module>
    TypeError: 'coroutine' object is not subscriptable

# Right
    sel = await db.tables['employees'][1000]
    sel['id]

Iterate through table - grab all rows - allowing client side filtering

async for row in db.tables['employees']:
    print(row['id], row['name'])
query:
    SELECT * FROM employees
result:
    1000 Frank Franklin
    1001 Eli Doe
    1002 Chris Smith
    1003 Clara Carson

Using list comprehension

sel = [(row['id'], row['name']) async for row in db.tables['employees']]
query:
    SELECT * FROM employees
result:
    [
        (1000, 'Frank Franklin'), 
        (1001, 'Eli Doe'), 
        (1002, 'Chris Smith'), 
        (1003, 'Clara Carson'),
        ...
    ]

Update Data

Define update values in-line or un-pack

await db.tables['stocks'].update(
    symbol='NTAP',trans='SELL', 
    where={'order_num': 1}
    )
query:
    UPDATE stocks 
            SET 
                symbol = 'NTAP', 
                trans = 'SELL' 
            WHERE 
                order_num=1

Un-Pack

# JSON Serializable Data 
tx_data = {
    'type': 'BUY', 
    'condition': {
        'limit': '36.00', 
        'time': 'end_of_trading_day'
        }
    }
to_update = {
    'symbol': 'NTAP', 
    'trans': tx_data # dict
    }

await db.tables['stocks'].update(
    **to_update, 
    where={'order_num': 1}
    )
query:
    UPDATE stocks 
        SET 
            symbol = 'NTAP', 
            trans = '{"type": "BUY", "condition": {"limit": "36.00", "time": "end_of_trading_day"}}' 
        WHERE 
            order_num=1

Bracket Assigment - Primary Key name assumed inside Brackets for value

#JSON Serializable Data 

tx_data = {
    'type': 'BUY', 
    'condition': {
        'limit': '36.00', 
        'time': 'end_of_trading_day'
        }
    }
to_update = {
    'symbol': 'NTAP', 
    'trans': tx_data, # dict
    'qty': 500}

# Synchronus only
db.tables['stocks'][2] = to_update 

# Asynchronus
await db.tables['stocks'].set_item(2, to_update)

query:
    # check that primary_key value 2 exists
    SELECT * FROM stocks WHERE order_num=2

    # update 
    UPDATE stocks 
        SET
            symbol = 'NTAP', 
            trans = '{"type": "BUY", "condition": {"limit": "36.00", "time": "end_of_trading_day"}}', 
            qty = 500 
        WHERE order_num=2

result:
    await db.tables['stocks'][2]

    # beutified
    {
        'order_num': 2, 
        'date': '2006-01-05', 
        'trans': {
            'type': 'BUY', 
            'condition': {
                'limit': '36.00', 
                'time': 'end_of_trading_day'
            }
        }, 
        'symbol': 'NTAP', 
        'qty': 500, 
        'price': 35.16, 
        'after_hours': True
    }

Delete Data

await db.tables['stocks'].delete(
    where={'order_num': 1}
    )