sqlify 0.7.4
A simple sql builder based on standard Python type hints
Requires Python: >=3.7.0

# [Sqlify](https://github.com/g4brym/Sqlify)
This project is a fork from [pg_simple](https://github.com/masroore/pg_simple), that tries to implement a standard SQL
with python type hinting interface.
This fork also implements extra parameters like having or with queries.
Other goals for this project is to support other types of databases like sqlite.

[Read full documentation here](https://sqlify.massadas.com/)

The [Sqlify](https://github.com/g4brym/Sqlify) module provides a simple standardized interface while keeping the 
benefits and speed of using raw queries over `psycopg2` or `sqlite3`
This module is ment to work as a query builder, and you must provide your own integrations and session pooling if you want.

`sqlify` is not intended to provide ORM-like functionality, rather to make it easier to interact with the database from 
python code for direct SQL access using convenient wrapper methods.

The `sqlify` module provides:

* Python typed interface that can scale from just basic queries to some complex queries, for example using the
[PostgreSQL With](https://www.postgresql.org/docs/9.1/queries-with.html)
* Python API to wrap basic SQL functionality: select, update, delete, join et al
* Query results as python dict objects
* Inserts/Updates/Deletes returning data as dict objects or the affected rows count
* Auto commit/rollback when finishing one or multiple queries
* Database migration tools
* Typer cli for migration commands
* Bulk insert (WIP)
* On the fly error prevention when developing with a smart IDE like pycharm (due to the advanced type hinting)
* Debug logging support


## Installation

With `pip` or `easy_install`:

```pip install sqlify```

or:

```easy_install sqlify```

or from the source:

```python setup.py install```


## 30 Seconds Quick-start Guide

* Step 1: Connect to the database of your choice
* Step 2: Using the Session class pass through the connection
* Step 3: Enjoy your queries

Here's a pseudo-example to illustrate the basic concepts:

```python
import sqlite3
from sqlify import Session

conn = sqlite3.connect('my_test.db')
with Session(conn, autocommit=True) as sqlify:
    rest = sqlify.fetchone(
        table="test",
        fields="column_1",
    )
```


## Basic Usage

### Connecting to the posgtresql server

The following snippet will connect to the posgtresql server and allocate a cursor:

```python
import psycopg2
from sqlify import Session

conn = psycopg2.connect("host=localhost dbname=test user=postgres password=postgres")
with Session(conn, autocommit=True) as sqlify:
    rest = sqlify.fetchone(
        table="test",
        fields="column_1",
    )
```

By default `psycopg2` generates result sets as `collections.namedtuple` objects (using `psycopg2.extras.NamedTupleCursor`). 
But because `sqlify` is connection agnostic you can easily modify it to use the `DictCursor` that returns a `Dict` object

```python
import psycopg2
from psycopg2.extras import DictCursor

conn = psycopg2.connect("host=localhost dbname=test user=postgres password=postgres", cursor_factory=DictCursor)
```

If you don't like context based interfaces (aka [with statement](https://www.geeksforgeeks.org/with-statement-in-python/))
or it doesn't fit your architecture you can also assign it to a variable and use it as you did expect.
But remember that by using it this way you lost the auto-commit/rollback feature and auto-close of the database connection

```python
sqlify = Session(conn, autocommit=True).session
rest = sqlify.fetchone(
    table="test",
    fields="column_1",
)

sqlify.commit()
sqlify.close()
```

### Fetching a single record

```python
with Session(conn, autocommit=True) as sqlify:
    book = sqlify.fetchone(
        table='books', 
        fields="*",
        where=(
            "published = %(publish_date)s",
            dict(
                publish_date=datetime.date(2002, 2, 1),
            ),
        ),
    )
                   
print(f"{book.name} was published on {book.published}")
```

### Fetching multiple records

```python
from sqlify import Order

with Session(conn, autocommit=True) as sqlify:
    books = sqlify.fetchone(
        table='books',
        fields=['name AS n', 'genre AS g'],
        where=(
            [
                "published BETWENN %(since)s and %(to)s",
                "gender = %(gender)s",
            ],
            dict(
                since=datetime.date(2005, 2, 1),
                to=datetime.date(2009, 2, 1),
                gender="fiction",
            ),
        ),
        order=("published", Order.DESC),
        limit=5,
        offset=2,
    )

for book in books:
    print(f"{book.name} was published on {book.published}")
```

### Raw SQL execution

In raw queries you can use both `list` and `dict` annotations

```python
with Session(conn, autocommit=True) as sqlify:
    sqlify.execute('SELECT tablename FROM pg_tables WHERE schemaname=%s and tablename=%s', ['public', 'books'])
    sqlify.execute('SELECT name FROM books WHERE author=%(author)s', {"author": "Andre"})
```

### Inserting rows

```python
with Session(conn, autocommit=True) as sqlify:
    for i in range(1, 10):
        sqlify.insert(
            table="books",
            data=dict(
                name=f"Book Name vol. {i}",
                price=1.23 * i,
                genre="fiction",
                published=f"{2000 + i}-{i}-1",
            ),
        )

    # DB commit is already called when the session context exits without any exception
    # You can disable this with autocommit=False
```

### Updating rows

```python
from sqlify import RawSQL

with Session(conn, autocommit=True) as sqlify:
    affected_rows = sqlify.update(
        table="books",
        where=(
            "published = %(published)s",
            dict(
                published=datetime.date(2001, 1, 1)
            ),
        ),
        data=dict(
            genre="non-fiction",
            modified=RawSQL("now()"),
        ),
    )
    
    # Commit is implicit
    
print(f"Lines updated in this query: {affected_rows}")
```

### Deleting rows

```python
with Session(conn, autocommit=True) as sqlify:
    deleted_rows = sqlify.delete(
        table="books",
        where=(
            "published >= %(published)s",
            dict(published=datetime.date(2005, 1, 31)),
        ),
    )

    # Commit is implicit

print(f"Lines deleted in this query: {deleted_rows}")
```

### Dropping and creating tables

```python
with Session(conn, autocommit=True) as sqlify:
    sqlify.drop('books')

    sqlify.create('books',
        '''
        "id" SERIAL NOT NULL,
        "type" VARCHAR(20) NOT NULL,
        "name" VARCHAR(40) NOT NULL,
        "price" MONEY NOT NULL,
        "published" DATE NOT NULL,
        "modified" TIMESTAMP(6) NOT NULL DEFAULT now()
        '''
    )

    sqlify.execute('''ALTER TABLE "books" ADD CONSTRAINT "books_pkey" PRIMARY KEY ("id")''')

    # Commit is implicit
```

### Emptying a table or set of tables

```python
with Session(conn, autocommit=True) as sqlify:
    sqlify.truncate('tbl1')
    sqlify.truncate('tbl2, tbl3', restart_identity=True, cascade=True)

    # Commit is implicit
```

### Inserting/updating/deleting rows with return value

```python
with Session(conn, autocommit=True) as sqlify:
    row = sqlify.insert(
        table="books",
        data=dict(
            name=f"Book Name vol. {i}",
            price=1.23 * i,
            genre="fiction",
            published=f"{2000 + i}-{i}-1",
        ),
        returning="id",
    )
print(row.id)

with Session(conn, autocommit=True) as sqlify:
    rows = sqlify.update(
        table="books",
        where=(
            "published = %(published)s",
            dict(
                published=datetime.date(2001, 1, 1)
            ),
        ),
        data=dict(
            genre="non-fiction",
            modified=RawSQL("now()"),
        ),
        returning="*",
    )
for row in rows:
    print(row.modified)

with Session(conn, autocommit=True) as sqlify:
    rows = sqlify.delete(
        table="books",
        where=(
            "published >= %(published)s",
            dict(published=datetime.date(2005, 1, 31)),
        ),
        returning="name",
    )
for row in rows:
    print(row.name)
```

### Explicit database transaction management

```python
with Session(conn, autocommit=False) as sqlify:
    try:
        sqlify.execute('Some SQL statement')
        sqlify.commit()
    except:
        sqlify.rollback()
```

### Implicit database transaction management

```python
with Session(conn, autocommit=True) as sqlify:
    sqlify.execute('Some SQL that trows an error')
    # Rollback will automatically be called and the exception will continue down the execution tree
```

The above transaction will be rolled back automatically should something goes wrong.