MySQL: Get column name or alias from query

Question

I\'m not asking for the SHOW COLUMNS command.

I want to create an application that works similarly to heidisql, where you can specify an SQL query and w

Answer 1

Looks like MySQLdb doesn't actually provide a translation for that API call. The relevant C API call is mysql_fetch_fields, and there is no MySQLdb translation for that

Answer 2

You could also use MySQLdb.cursors.DictCursor. This turns your result set into a python list of python dictionaries, although it uses a special cursor, thus technically less portable than the accepted answer. Not sure about speed. Here's the edited original code that uses this.

#!/usr/bin/python -u

import MySQLdb
import MySQLdb.cursors

#===================================================================
# connect to mysql
#===================================================================

try:
    db = MySQLdb.connect(host='myhost', user='myuser', passwd='mypass', db='mydb', cursorclass=MySQLdb.cursors.DictCursor)
except MySQLdb.Error, e:
    print 'Error %d: %s' % (e.args[0], e.args[1])
    sys.exit(1)

#===================================================================
# query select from table
#===================================================================

cursor = db.cursor()

sql = 'SELECT ext, SUM(size) AS totalsize, COUNT(*) AS filecount FROM fileindex GROUP BY ext ORDER BY totalsize DESC;'

cursor.execute(sql)
all_rows = cursor.fetchall()

print len(all_rows) # How many rows are returned.
for row in all_rows: # While loops always make me shudder!
    print '%s %s %s\n' % (row['ext'], row['totalsize'], row['filecount'])

cursor.close()
db.close()  

Standard dictionary functions apply, for example, len(row[0]) to count the number of columns for the first row, list(row[0]) for a list of column names (for the first row), etc. Hope this helps!

Answer 3

Something similar to the proposed solutions, only the result is json with column_header : vaule for db_query ie sql.

cur = conn.cursor()
cur.execute(sql)
res = [dict((cur.description[i][0], value) for i, value in enumerate(row)) for row in cur.fetchall()]

output json example:

[
   {
      "FIRST_ROW":"Test 11",
      "SECOND_ROW":"Test 12",
      "THIRD_ROW":"Test 13"
   },
   {
      "FIRST_ROW":"Test 21",
      "SECOND_ROW":"Test 22",
      "THIRD_ROW":"Test 23"
   }
]

Answer 4

This is only an add-on to the accepted answer:

def get_results(db_cursor):
    desc = [d[0] for d in db_cursor.description]
    results = [dotdict(dict(zip(desc, res))) for res in db_cursor.fetchall()]
    return results

where dotdict is:

class dotdict(dict):
    __getattr__ = dict.get
    __setattr__ = dict.__setitem__
    __delattr__ = dict.__delitem__

This will allow you to access much easier the values by column names.
Suppose you have a user table with columns name and email:

cursor.execute('select * from users')
results = get_results(cursor)
for res in results:
  print(res.name, res.email)

Answer 5

I think this should do what you need (builds on the answer above) . I am sure theres a more pythony way to write it, but you should get the general idea.

cursor.execute(query)
columns = cursor.description
result = []
for value in cursor.fetchall():
    tmp = {}
    for (index,column) in enumerate(value):
        tmp[columns[index][0]] = column
    result.append(tmp)
pprint.pprint(result)

Answer 6

Try:

cursor.column_names

mysql connector version:

mysql.connector.__version__
'2.2.9'