Oracle: row-wise comparison

I had a query that needed to compare two columns in a row andwas making two queries to do so. All hail the row-wise comparison!

select id from p4_versions
where (versionof, version) = (select id, headver from p4_files
      where p4path like '%/date.txt');

How to Create a REST Protocol

"REST is an architectural style that can be used to guide the construction of web services. Recently, there have been attempts to create such services that have met with mixed success. This article outlines a series of steps you can follow in creating your protocol--guidance that will help you get all the benefits that REST has to offer, while avoiding common pitfalls."

How to Create a REST Protocol

Python: retrieving the oracle error code

Anthony Tuininga gave me this hint on retrieving the Oracle error code from a cx_python program:

try:
    cursor.execute("select 1 / 0 from dual")
except cx_Oracle.DatabaseError, e:
    print "Exception:", e    # this is what you are looking at right now
    errorObj, = e.args       # this is the actual "error" that cx_Oracle raises
    print "ErrorCode:", errorObj.code
    print "ErrorMessage:", errorObj.message

Causing Guido van Rossum to ask

This is overly subtle. Why not write

    errorObj = e.args[0]

and received the response

No particularly good reason -- it just happens to be a way of indicating that there should be one and only one entry in the list. An exception is raised if there is not whereas args[0] does not raise the exception. Its an open question which is the better code.