How to cast date to string in psycopg2?

问题

I'm sure it has something to do with registering custom type cast as described here. However, I'm not sure how to do that.

What I want to do is something like this: SELECT * FROM table and where a column is of date type, I want psycopg2 to convert it to Python string instead of datetime.

回答1:

I found how to do it:

def register_New_Date():
    # Cast PostgreSQL Date as Python string
    # Reference:
    # 1. http://initd.org/psycopg/docs/extensions.html#psycopg2.extensions.new_type
    # 2. http://initd.org/psycopg/docs/advanced.html#type-casting-from-sql-to-python
    # 1082 is OID for DATE type.
    NewDate = psycopg2.extensions.new_type((1082,), 'DATE', psycopg2.STRING)
    psycopg2.extensions.register_type(NewDate)

Then run:

register_New_Date()

来源：https://stackoverflow.com/questions/32184465/how-to-cast-date-to-string-in-psycopg2