chocolatine 0.90.0

Dynamic generation of SQL queries

chocolatine

Chocolatine is a python library for dynamicaly generate SQL queries.

Why Chocolatine ?

If you know Python programming langage but you are not at your ease with SQL (or you don't want to manage SQL queries by yourself), you can use Chocolatine to generate some SQL queries for you. Of course, there are many other open source projects to do that, but honestly, they are more complex than most people expects from them (SQLAlchemy, Django ORM, etc...).

Installation

pip install chocolatine

Examples

Concatenation & filtering :

from chocolatine import Query, Col as _

query = Query().table("customer")\
               .select(
                    "customer_id",
                    (_("first_name") & ' ' & _("last_name")).upper().alias("name")
                )\
               .filter(_("first_name") >> "%E")
print(query)

Output :

SELECT customer_id, UPPER(CONCAT(first_name, ' ', last_name)) AS name
FROM customer
WHERE first_name LIKE '%E'

Group by, aggregation & filtering :

from chocolatine import Query, sum, Col as _

query = Query().table("payment")\
               .select(
                    "customer_id",
                    count().alias("payment_count"),
                    sum("amount").alias(">:total_amount")
                )\
               .group_by("customer_id")\
               .filter(count() > 1 & sum("amount") > 5.00)\
               .filter(_("customer_id") != 3)
print(query)

Output :

SELECT customer_id, COUNT(*) AS payment_count, SUM(amount) AS total_amount
FROM payment
WHERE customer_id != 3
GROUP BY customer_id
HAVING COUNT(*) > 1 AND SUM(amount) > 5.00
ORDER BY total_amount

Join :

from chocolatine import Query, Col as _

query = Query().table("film")\
               .select(
                    "title",
                    "film_id",
                    (_("first_name") & " " & _("last_name")).alias("name")
                )\
               .join("film_actor", "film_id")\
               .join("actor", "actor_id")\
               .build()
print(query)

Output :

SELECT title, film_id, CONCAT(first_name, ' ', last_name) AS name
FROM film
INNER JOIN film_actor
USING film_id
INNER JOIN actor
USING actor_id

SQL dialect

For now, Chocolatine is only designed to generate MySQL queries.

Basic functionnalities

• Select, Insert, Update, Create, Alter & Delete queries
• Distinct
• Limit
• Aliases
• Ordering
• Group by & aggregations
• Joins
• SQL functions
• Concatenations
• Unions
• Case-When
• Where / Having

Advanced functionnalities

• Dynamic type checking
• Protection against SQL injection attacks
• Calls orders doesn't matter (except for join clauses)
• Compact or extended SQL expressions
• Whole system to deal with conditions :
  • Logical operators : equal, not equal, greater, lower, etc...
  • Boolean operators : and, or, not
  • Priority order with parenthesis
• Automatic handling of filter conditions to fill the having or where clause depending on the given columns
• Shortcuts:
  • Alias on column/table name
  • Help functions : Asc, Desc, Sum, Count, Upper, Lower, Concat, Second, Minute, Hour, Day, Month, Year
  • Column ordering
  • Like/In
• Auto id on create queries (optionnal)
• Nested queries
• Choc-expr expression for SQL queries templating

Choc-expr library

• Choc-expr is a mini templating librairie specially designed to handle such complex langage as SQL
• It is a very conscise language designed for easy reading
• See https://github.com/pe-brian/choc-expr for more informations

Tests

python pytest

Install Sakila database (mySQL) with Docker

docker run -p 3306:3306 -d sakiladb/mysql:latest

Contributors

• peb-8 (main code)
• ryry-shi (testing)