pyql-db 2.1

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

pyql

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

Instalation

$ python3 -m venv myproj

$ source my-project/bin/activate

Install with PIP

 (myproj)$ pip install pyql-db   

Download & install Library from Github:

(myproj)$ git clone https://github.com/codemation/pyql.git

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

(myproj)$ cd pyql; sudo ./install.py install

Compatable Databases - Currently

• mysql
• sqlite

Getting Started

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

DB connection

    import sqlite3
    db = database(
        sqlite3.connect, 
        database="testdb"
        )

    import mysql.connector

    db = database(
        mysql.connector.connect,
        database='mysql_database',
        user='mysqluser',
        password='my-secret-pw',
        host='localhost',
        type='mysql'
        )

Table Create

Requires List of at least 2 item tuples, max 3

('ColumnName', type, 'modifiers')
    ColumnName - 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: constraints are not validated by pyql but at db, so if modifier is supported it will be added when table is created.

# Table Create    
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)

Insert Data

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

tb = db.tables['stocks']

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

# Special Data 
Columns of type string can hold JSON dump-able python dictionaries as JSON strings and are automatically converted back into dicts when read.

txData = {
    'type': 'BUY', 
    'condition': {'limit': '36.00', 'time': 'EndOfTradingDay'} #  Dict Value 
    }

Select Data

Use * for all columns Use col1,col2,col3 to select specific columns

tb = db.tables['stocks']

# Bracket indexs can only be used for primary keys and return all column values 
sel = tb[0] # Select * from stocks where order_num = 1

# If using WHERE condition for non-primary key column, where={'col': <val>} is required
sel = tb.select('*', where={'symbol': 'RHAT'}) # select * from stocks where symbol = 'RHAT'

# Iterate through table - grab all rows
sel = [row for row in tb] # select * from stocks

In:
    print(sel)
Out:
    [
        {'order_num': 1, 'date': '2006-01-05', 'trans': 'BUY', 'symbol': 'RHAT', 'qty': 100.0, 'price': '35.14'},
        {'order_num': 2, 'date': '2006-01-06', 'trans': 'BUY', 'symbol': 'RHAT', 'qty': 100.0, 'price': '35.14'},
        ..
    ]

Update Data

Define update values in-line or un-pack

    tb = db.tables['stocks']

    # in-line
    tb.update(
        symbol='NTAP',trans='SELL', 
        where={'order_num': 1})

    is the same as 

    # Un-Pack
    toUpdate = {'symbol': 'NTAP', 'trans': 'SELL'}
    where = {'order_num': 1}

    tb.update(
        **toUpdate,
        where=where
    )

    is the same as 

    # Primary-Key - Where [] 
    tb[1] = toUpdate # Primary Key is assumed in brackets 
    tb[1] = {'qty': 200}

Delete Data

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