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atc2146 / pysqlgui

⚡ A lightweight package for interfacing with SQL in Python

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⚡ Pysqlgui

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Pysqlgui is a lightweight package for interfacing with SQL in Python. You can run SQL queries on Pandas DataFrames.

📚 Features

  • Create in memory databases.
  • Run any valid SQL query.
  • Clean and visually appealing query results with column names.
  • Import tables from CSV files or Pandas DataFrames.
  • Easily rename, create, or drop tables without writing long and complex queries.
  • Easily retrieve table information such as column type, default values, null constraints, and key constraints.
  • Helpful error messages.
  • And more.

📝 Usage

Using Pysqlgui is easy.

import pysqlgui

# Load a file and name the table
stores = pysqlgui.Database(['customers.csv'], ['CUSTOMERS'])

# Run a query
stores.run_query('SELECT * FROM CUSTOMERS;')

If you are running code in a Jupyter Notebook, the output will be a Pandas DataFrame. Otherwise, call print on the line above to print out the query result.

Note: you can pass other data formats or no data at all! Refer to detailed documentation below.

🖥️ Installation

From PyPi:

$ pip install pysqlgui

Upgrade to latest version 1.0.1 (Released June 14, 2020)

$ pip install pysqlgui --upgrade

📖 Quick Guide

Instantiate a Database object and pass any data if you wish.

your_database_name = pysqlgui.Database()

Then call any of the methods below!

Method Summary
Database.run_query(query) Run a SQL query.
Database.show(table_name) Show the contents of a table.
Database.info(table_name=None) Summary information about the database. Pass a table name as an argument to get table information.
Database.create_table(table_name, column_data) Create an empty table.
Database.add_table(data, table_names=None) Add a table to the database from a CSV file or Pandas DataFrame.
Database.insert_data(table_name, data) Insert data into a table.
Database.drop_table(table_name) Drop a table.
Database.rename_table(table_name, change_to) Rename a table.

📄 Detailed Documentation

Creating a database

pysqlgui.Database(data=None, table_names=None, name=None)

Parameters

  • data : list or dict, default=None, Optional
    • Can be a list (of filepaths to CSVs, or of Pandas DataFrames), or a dict where the key is the table name and the value is the filepath to the CSV or a Pandas DataFrame.
  • table_names : list, default=None, Optional
    • List of names of the tables, must be provided if data is of type list.
  • name : str, default=None, Optional
    • Name given to the database.
import pysqlgui as psg
import pandas as pd

# empty database
db_example_1 = psg.Database()

# from csv file via list notation
db_example_2 = psg.Database(['customers.csv'], ['CUSTOMERS'])

# from csv file via dict notation
db_example_3 = psg.Database({'CUSTOMERS': 'customers.csv'})

# from a Pandas DataFrame
df = pd.DataFrame({'name': ['John', 'Mary'], 'age': [32, 18]})
db_example_4 = psg.Database([df], ['USERS'])

# from a combination
db_example_5 = psg.Database([df, 'customers.csv'], ['USERS', 'CUSTOMERS'])
db_example_6 = psg.Database({'CUSTOMERS': 'customers.csv', 'USERS': df})

Run a SQL query

pysqlgui.Database.run_query(query)

Runs a SQL query.

Parameters

  • query : str
    • A SQL query.

Returns

  • Pandas DataFrame, or None
    • Returns a Pandas DataFrame if the query is of SELECT or PRAGMA type, None otherwise. Note, all valid SQL is allowed including CREATE, INSERT, DROP, etc.
import pysqlgui as psg
import pandas as pd

# SELECT data
df = pd.DataFrame({'name': ['John', 'Mary'], 'age': [32, 18]})
my_db = psg.Database([df], ['USERS'])
my_db.run_query('SELECT * FROM USERS;')

Show table

pysqlgui.Database.show(table_name)

Shows the contents of a table. Equivalent to SELECT * FROM.

Parameters

  • table_name : str
    • The table to show.

Returns

  • Pandas DataFrame
    • Pandas DataFrame of the table contents.
import pysqlgui as psg
import pandas as pd

my_db = core_database.Database([pd.DataFrame([['tom', 10], ['bob', 15]], columns=['name', 'age'])],['USERS'])
my_db.show('USERS')

Summary information about the database

pysqlgui.Database.info(table_name=None)

Returns summary information about the database or a table.

Parameters

  • table_name : str, default=None, Optional
    • The name of the table. If a name is not provided, returns summary information about the database.

Returns

  • Pandas DataFrame
    • Returns summary database or table information in a Pandas DataFrame.
import pysqlgui as psg
import pandas as pd

df = pd.DataFrame({'name': ['John', 'Mary'], 'age': [32, 18]})
my_db = psg.Database([df], ['USERS'])

my_db.info() # database info
my_db.info('USERS') # table info

Create an empty table

pysqlgui.Database.create_table(table_name, column_data)

Creates an empty table in the database. See SQLite Datatypes.

Parameters

  • table_name : str

    • The name of the table to be created.

  • column_data : dict

    • Keys are the column names, and values are the type with any properties.

Returns

  • None
import pysqlgui as psg
import pandas as pd

my_db = psg.Database()
my_db.create_table('users',
                    {'user_id': 'INTEGER',
                    'first_name': 'TEXT',
                    'join_date': 'DATE',
                    'score': 'FLOAT'})

# create tables with additional properties
my_db_2 = psg.Database()
my_db_2.create_table('users',
                    {'user_id': 'INTEGER PRIMARY KEY AUTOINCREMENT',
                    'first_name': 'TEXT',
                    'join_date': 'DATE'})
my_db_2.create_table('articles',
                    {'article_id': 'INTEGER PRIMARY KEY',
                    'article_name': 'TEXT',
                    'written_by': 'INTEGER REFERENCES users(user_id)'})

Add a table

pysqlgui.Database.add_table(data, table_names=None)

Adds one or more Table objects to the current Database instance.

Parameters

  • data : list or dict
    • Can be a list (of filepaths to CSVs, or of Pandas DataFrames), or a dict where the key is the table name and the value is the filepath to the CSV or a Pandas DataFrame.
  • table_names : list, default=None, Optional
    • List of names of the tables, must be provided if data is of type list.

Returns

  • None
import pysqlgui as psg
import pandas as pd

my_db = psg.Database()
df = pd.DataFrame({'name': ['John', 'Mary'], 'age': [32, 18]})
my_db.add_table([df], ['USERS'])

Insert data

pysqlgui.Database.insert_data(table_name, data)

Inserts data into the table. Highly recommended to add via Pandas DataFrame.

Parameters

  • table_name : str
    • The name of the existing table to add data.
  • data : Pandas DataFrame or dict
    • Pandas DataFrame with the corresponding columns. Or a dict where keys are the column names, and values are the column value.

Returns

  • None
import pysqlgui as psg
import pandas as pd

my_db = psg.Database([pd.DataFrame({'name': ['John', 'Mary'], 'age': [32, 18]})],
                     ['USERS'])

my_db.insert_data('USERS', pd.DataFrame({'name': ['Bob', 'Simram'], 'age': [22, 5]}))
my_db.insert_data('USERS', {'name': 'Jordan', 'age': 23})

Drop a table

pysqlgui.Database.drop_table(table_name)

Drops a table in the database.

Parameters

  • table_name : str
    • The name of the table to be dropped.

Returns

  • None
import pysqlgui as psg
import pandas as pd

my_db = psg.Database([pd.DataFrame({'name': ['John', 'Mary'], 'age': [32, 18]})],
                     ['USERS'],
                     'MY_DB_NAME')
my_db.drop_table('USERS')

Rename a table

pysqlgui.Database.rename_table(table_name, change_to)

Renames a table in the database.

Parameters

  • table_name : str
    • The name of the table to be renamed.
  • change_to : str
    • The new name of the table.

Returns

  • None
import pysqlgui as psg
import pandas as pd

my_db = psg.Database([pd.DataFrame({'name': ['John', 'Mary'], 'age': [32, 18]})],
                     ['USERS'],
                     'MY_DB_NAME')
my_db.rename_table('USERS', 'USERS_NEW_NAME')

⚙️ Development

Pysqlgui is built on the sqlite3 standard library.

The sqlite3 Connection Object and Cursor Object is available to you:

Database.connection
Database.cursor

You can find sample data used for some of the examples here.

✏️ Contributing

Clone the repo

$ git clone https://github.com/atc2146/pysqlgui.git

©️ License

MIT © 2020 Alex Chung

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⚡ A lightweight package for interfacing with SQL in Python

databasedataframejupyter-notebookpandaspythonsqlsqlitesqlite3

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