Table of Contents

  1. GnrSql Overview
    1. GnrSqlDb
    2. Database model
    3. Accessing the db
    4. Getting data
  2. Quick Start
    1. Use Genro on your SQL db
      1. Connecting to database
      2. Reading database Model
      3. Build the Model objects hierarchy
      4. Explore the model
      5. Selection
      6. Record
      7. Surfing data through relations
  3. Database model
    1. Model Source
      1. Writing a DbModelSrc in Python
        1. Adding package
        2. Adding tables
        3. Adding columns
        4. Adding relations
        5. Adding indexes
      2. Python vs. XML
    2. Model Object
  4. Query
      1. parameter: columns
      2. parameter where
      3. parameter relationDict
  5. Records
    1. record come bag
    2. campi primari
    3. campi in relazione ascendente
    4. campi in relazione discendente
    5. uso formule
    6. browsing automatico da un record nelle relazioni
    7. creazione nuovi record
    8. salvataggio di record
    9. modifica
    10. cancellazione
    11. trigger
    12. gestione record di transazione
  6. Creation and editing
    1. Esempi pratici

GnrSql Overview

The GenroSql library is the main tool that genropy project uses to handle database in Python. We decided to make it available as an independent package. At this time there are 2 db adapters: one for PostgresSQL one for sqlite. We hope that soon will be avaliable adpaters for Firebird, Mysql and other Dbms.

GnrSqlDb

Is the core class of GenroSql. GnrSqlDb performs these assignments:

  • handling dbms
  • accessing the database
  • managing and exporting data
  • others

Database model

GnrSqlDb has a Model which represents the database structure. The Model contains a recipe of the database called Source and a hierarchy of objects that handle all db elements (tables, columns etc.).

You can import the model from an existig db or define it importing an XML file or using some python easy functional call.

Accessing the db

GnrSqlDb has a particular way to do query. In fact we can say that a query in our sql handler starts from the point of view of a single table (the same of the SQL statement FROM).

So in the query method of Table you can select columns belong to the table instance itself but also all the columns of the tables related to the starting table through an automatic join management.

The method query return the stored query as a new SqlQuery? instance

Getting data

A way to manage the extracted data is the SqlSelection? object. An SqlSelection? instance is created by the selection() method of SqlQuery?. You can sort, filter, store export the data into SqlSelection?. You can export the data into differents format through output SqlSelection? method.

You can also get fetch, cursor, servercursor etc. directly from SqlQuery?.

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