Sanitized queries in pyodbc returns only the field name

Question

When I query my SQL server with pyodbc, I get only the name of the field I requested (instead of the values itself).

import pyodbc

conn = pyodbc.connect(connection_string)
cursor = conn.cursor()
cursor.execute('SELECT ? FROM [Projects]', '[ProjectNo]')
for row in cursor.fetchall():
    print(row)

This prints the following:

('[ProjectNo]', )
('[ProjectNo]', )
('[ProjectNo]', )
('[ProjectNo]', )
('[ProjectNo]', )
('[ProjectNo]', )
('[ProjectNo]', )
('[ProjectNo]', )
('[ProjectNo]', )

The number of lines is equal to the number of rows in the Projects table. I have the same issue when the second argument in cursor.execute is "[ProjectNo]", "ProjectNo", or even "blahblahblahblah"; each row only gives the requested field's name.

I do not have this problem if I use only one argument in cursor.execute:

cursor.execute('SELECT [ProjectNo] FROM [Projects]')

This will return what I expect it to.

What am I missing here?

You can't use parameters for the db objects (columns, tables..). Use it for values only. — Serg, Oct 16 '19 at 12:22
@Serg Aha, of course. I remembered having this problem before, and that the answer was obvious. Thank you — joedeandev, Oct 16 '19 at 12:23

score 1 · Answer 1 · answered Oct 16 '19 at 13:08

1

You can use like this,

import pyodbc

conn = pyodbc.connect(connection_string)
cursor = conn.cursor()
cursor.execute('SELECT {} FROM [Projects]".format('[ProjectNo]'))
for row in cursor.fetchall():
    print(row)

answered Oct 16 '19 at 13:08

Thangadurai.B

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score 0 · Accepted Answer · answered Nov 22 '19 at 13:23

0

As Serg answered in a comment:

Column names can't be a variable parameter in a constructed query/statement. Only values can be a parameter.

answered Nov 22 '19 at 13:23

joedeandev

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Can you show some code for your solution? – Milo Persic Nov 28 '22 at 23:14

Sanitized queries in pyodbc returns only the field name

2 Answers2