IronPython, PetaPoco, and .Net 4 'dynamic'

-
Recently I was playing around with IronPython and PetaPoco (a .Net micro-ORM). PetaPoco allows the use of the 'dynamic' keyword when querying data. Unfortunately, the dynamic keyword is not available in IronPython. However, since IronPython makes use of the DLR, its types are already dynamic instances. Therefore, all I needed to do was provide a Python type instead of the dynamic keyword (I used 'object'). The end result is an interesting combination of Oracle, PetaPoco, .Net 4, and IronPython.


import clr
import csv

clr.AddReferenceToFile("Oracle.DataAccess.dll")
clr.AddReferenceToFile("PetaPoco.dll")

import Oracle.DataAccess.Client
import PetaPoco

conString = "user id=USER;data source=DB;password=PASS"
provider = Oracle.DataAccess.Client.OracleClientFactory()
db = PetaPoco.Database(conString, provider)

query = "select * from my_table"
result = db.Fetch[object](query)

csvFile = csv.writer(open('out.csv', 'wb'))

if result.Count > 0:
hdrs = [header.Key for header in result[0]]
csvFile.writerow(hdrs)

for rec in result:
vals = [col.Value for col in rec]
csvFile.writerow(vals)

Comments

Post a Comment

Popular posts from this blog

Form.Show() From Another THread - C#.Net

-
Today I ran into a mojor headache. I have a main form that instantiates a secondary form from its constructor. I also register to a receive data event that I have based on a socket. Because the socket uses threading, when my event delegate is called, it is being called from the context of another thread. It is inside the execution of the delegate that I ran into trouble. When I receive data from the socket, I want to open the secondary form and do something with it. Immediately I know that I am going to have to use Invoke on the secondary form in order to safely modify it from the other thread. My original attempt looked like this (I will use an inline delegate here to simplify this listing): void dataReceived() { If(secondaryForm.InvokeRequired) { MethodInvoker myDelegate = delegate { secondaryForm.Show(); //do other work on secondaryForm }; secondaryForm.Invoke(myDelegate)
Read more

Hello World

-
This blog will be my attempt to keep track of random coding techniques that I run across, or anything else code related that I find useful. If all goes well, I will begin adding posts soon.
Read more

A Quick Note On Ports and Sockets

-
At this point, most people are familiar with the use of an IP address. Basically it is a unique number used on a network to identify a network computer. When we talk about computers communicating with each other, an IP address alone is useless. A single computer may have many programs running that want to communicate over the network. This means that a single address point (the IP address) is not enough to define what program a remote computer would like to communicate with. This is where port numbers come in. A program can bind itself to one or many open ports (meaning they are not currently in use by another program). Once bound to a port, a remote computer can communicate with a program by addressing the computer's address (IP) along with the program's address on that computer (Port). A common misconception is that a socket represents a bound port on a computer (the IP:Port pair). In reality, this is only half of what a socket represents. In fact, a socket represe
Read more