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74 lines
2.3 KiB
ReStructuredText
74 lines
2.3 KiB
ReStructuredText
=======================================
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psycopg 2 extensions to the DBAPI 2.0
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=======================================
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This document is a short summary of the extensions built in psycopg 2.0.x over
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the standard `Python Database API Specification 2.0`__, usually called simply
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DBAPI-2.0 or even PEP-249. Before reading on this document please make sure
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you already know how to program in Python using a DBAPI-2.0 compliant driver:
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basic concepts like opening a connection, executing queries and commiting or
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rolling back a transaction will not be explained but just used.
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__ http://www.python.org/peps/pep-0249.html
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Connection and cursor factories
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===============================
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psycopg 2 exposes two new-style classes that can be sub-classed and expanded to
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adapt them to the needs of the programmer: `cursor` and `connection`. The
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`connection` class is usually sub-classed only to provide a . `cursor` is much
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more interesting, because it is the class where query building, execution and
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result type-casting into Python variables happens.
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Row factories
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-------------
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tzinfo factories
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----------------
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Setting transaction isolation levels
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====================================
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Adaptation of Python values to SQL types
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========================================
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Type casting of SQL types into Python values
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============================================
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Extra type objects
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------------------
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Working with times and dates
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============================
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Receiving NOTIFYs
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=================
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Using COPY TO and COPY FROM
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===========================
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PostgreSQL status message and executed query
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============================================
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`cursor` objects have two special fields related to the last executed query:
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- `.query` is the textual representation (str or unicode, depending on what
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was passed to `.execute()` as first argument) of the query *after* argument
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binding and mogrification has been applied. To put it another way, `.query`
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is the *exact* query that was sent to the PostgreSQL backend.
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- `.statusmessage` is the status message that the backend sent upon query
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execution. It usually contains the basic type of the query (SELECT,
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INSERT, UPDATE, ...) and some additional information like the number of
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rows updated and so on. Refer to the PostgreSQL manual for more
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information.
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