Retrieving column values by column name with MySQLdb
Hi,
Is there a way of retrieving the value of columns in the rows returned by
fetchall, by column name instead of index on the row?
Code Snippet:
query=select * from employees
db=MySQLdb.connect(host=host,user=user,passwd=passwd,db=database)
cursor = db.cursor ()
cursor.execute (query)
rows = cursor.fetchall ()
for row in rows:
print row[0]
Instead of specifying the index of the row to retrieve the first column
(row[0]), I'd like to retrieve the value of the first column by column name.
Something like row.get('employee_id')
Is something of the sort possible with Mysqdb?
Thanks very much.
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Re: Retrieving column values by column name with MySQLdb
On Fri, Jun 19, 2009 at 8:16 PM, jorma kalajjk...@gmail.com wrote:
Hi,
Is there a way of retrieving the value of columns in the rows returned by
fetchall, by column name instead of index on the row?
Code Snippet:
query=select * from employees
db=MySQLdb.connect(host=host,user=user,passwd=passwd,db=database)
cursor = db.cursor ()
cursor.execute (query)
rows = cursor.fetchall ()
for row in rows:
print row[0]
Instead of specifying the index of the row to retrieve the first column
(row[0]), I'd like to retrieve the value of the first column by column name.
Something like row.get('employee_id')
Is something of the sort possible with Mysqdb?
Thanks very much.
Use a DictCursor:
import MySQLdb.cursors
.
.
.
cursor = db.cursor (MySQLdb.cursors.DictCursor)
cursor.execute (query)
rows = cursor.fetchall ()
for row in rows:
print row['employee_id']
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kushal
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Re: Retrieving column values by column name with MySQLdb
jorma kala wrote:
Hi,
Is there a way of retrieving the value of columns in the rows returned by
fetchall, by column name instead of index on the row?
Code Snippet:
query=select * from employees
db=MySQLdb.connect(host=host,user=user,passwd=passwd,db=database)
cursor = db.cursor ()
cursor.execute (query)
rows = cursor.fetchall ()
for row in rows:
print row[0]
Instead of specifying the index of the row to retrieve the first column
(row[0]), I'd like to retrieve the value of the first column by column name.
Something like row.get('employee_id')
Is something of the sort possible with Mysqdb?
Mike gave you a good answer, though I think it's MySQL specific.
For a more generic solution:
cursor.execute(query)
name_to_index = dict(
(d[0], i)
for i, d
in enumerate(cursor.description)
)
rows = cursor.fetchall()
for row in rows:
print row[name_to_index['employee_id']]
Or in case you have lots of column-names, a simple lambda can
ease the typing required:
for row in rows:
item = lambda col_name: row[name_to_index[col_name]]
print item('employee_id')
The built-in sqlite3 module also has a way to tell results to
come back as a dict[1]
Note in each case the column-name indexing is case-sensitive.
Hope this helps,
-tim
[1]
http://docs.python.org/library/sqlite3.html#sqlite3.Connection.row_factory
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Re: Retrieving column values by column name with MySQLdb
On Fri, 19 Jun 2009 15:46:46 +0100 jorma kala jjk...@gmail.com wrote: Is there a way of retrieving the value of columns in the rows returned by fetchall, by column name instead of index on the row? Try this: db = MySQLdb.Connection(host=host,user=user,passwd=passwd,db=database) db.query(query) result = db.store_result() data = result.fetch_row(maxrows=0, how=1) -- Mike Kazantsev // fraggod.net signature.asc Description: PGP signature -- http://mail.python.org/mailman/listinfo/python-list
Re: Retrieving column values by column name with MySQLdb
On Fri, 19 Jun 2009 10:32:32 -0500 Tim Chase python.l...@tim.thechases.com wrote: Mike gave you a good answer, though I think it's MySQL specific. I don't have to deal with MySQL frequently but I've remembered that I used got the fields out somehow, and now, looking at the code, I wonder myself, why how is 1 and wtf is this how, anyway!? ;) I can't seem to find any mention of such methods in documentation and even python source, guess they are implemented directly in underlying C lib. Hope I learned to abstract from such syntax since then, I sure do... -- Mike Kazantsev // fraggod.net signature.asc Description: PGP signature -- http://mail.python.org/mailman/listinfo/python-list
