Using SQLAlchemy reflection, how do I query for data in specific column?
testtable = Table('member', Metadata, autoload=True)
def TestConnection():
data = None
loopCounter = 0
for data in session.query(testtable).filter_by(is_active=1, is_deleted=0):
print(loopCounter + 1, data)
loopCounter += 1
if data is None:
raise Exception ("Could not find any data that matches your query")
else:
print("It worked!")
TestConnection()
The above query gives me all the data in all columns in the members table. What I want however is to get specific data from columns. E.g. I want to retrieve the username and password columns but I just can't get the syntax right. Below is what I have so far:
def TestConnection():
loopCounter = 0
for password, username in session.query(testtable).filter_by(is_active=1, is_deleted=0):
print(loopCounter + 1, data)
loopCounter += 1
if data is None:
raise Exception ("Could not find any data that matches your query")
else:
print("It worked!")
That fails with the error:
Traceback (most recent call last):
File "/home/workspace/upark/src/monitor.py", line 36, in <module>
TestConnection()
File "/home/workspace/upark/src/monitor.py", line 26, in TestConnection
for password, username in session.query(testtable).filter_by(is_active=1, is_deleted=0):
ValueError: too many values to unpack (expected 2)
Am working with Python3.2, SQLAchemy0.8 and mysqlconnector from Oracle.
EDIT: some slight progress
Just discovered that I can "filter" out the columns after all results have been returned as follows:
def TestConnection():
data = None
loopCounter = 0
for data in session.query(testtable).filter_by(is_active=1, is_deleted=0):
print(loopCounter + 1, data.password, data.username)
loopCounter += 1
if data is None:
raise Exception ("Could not find any data that matches your query")
else:
print("It worked!")
That will give:
1 pass1 userone
2 pass2 usertwo
But as you can see, that is after I've gotten all the columns back. What I want is to fetch data from only the columns I need. E.g. The Members table has got 10 columns. I only need to get data from two of those for efficiency.
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