SQLebra is an agnostic SQL library wrapper supporting python data types. It serves as an interface between python variables and an SQL database.
An SQLebra database is represented by a single table with columns:
- id: Unique identifier for each variable
- name: Variable name
- class: Name of the variable's python class
- key: Text index for the current row (see "Nested objects" below).
- ind: Numeric index for the current row (see "Nested objects" below).
- bool_val: Boolean value
- int_val: Integer value
- real_val: Real value
- txt_val: Text value
- child_id: Identifier of the rows child variable (see "Nested objects" below).
- root: 1 signals the main variable row.
- user_defined: 1 signals a user defined variable.
Python nested variables (e.g. list, tuple and dict) are represented as a root row (similar to a header) and a row for each of its elements/items. Columns 'key' and 'ind' are used to indexate nested objects.
When a value of a nested object is another nested object, a references to such object is specified in the 'child_id' column.
Example using an SQLite file named "filename.db":
from sqlebra.sqlite import SQLiteDB
# Save an integers and a dictionary to an SQL file database
with SQLiteDB('filename.db') as db:
db['x'] = 10
db['my_dict'] = {'a': 10, 'b': 20}
The SQLite file "filename.db" now contains variables x and my_dict. To retrieve them at a later stage:
with SQLiteDB('filename.db') as db:
x = db['x'].py
my_dict = db['my_dict'].py