如何在我的POSTGRES SQL查询中访问python中声明的变量的内容

Question

I am just getting my hand dirty with python, hence my question might look silly. Yeah, I have the following code as per of a class. The declared variable in python was to accepted input from the user and then cross checked the content of the variable with an POSTGRES SQL statement. See the code below;

def view_user(self):
    self.contact_modify = input('Please enter name to modify : ')
    contact_modify = self.contact_modify
    try:
        con = self.db_conn()
        print('We are connected to the db now')
    except:
        print('I can not find your database connection here')

    try:
        print(contact_modify) # to check the content of the variable
        con.execute("SELECT * FROM phone WHERE address_name = :'contact_modify'")
        print(contact_modify) # To check the contents of the variable
        while True:
            row = con.fetchone()
            if row == None:
                break
            print(row[1],row[2],row[3])
    except:
        print("Error displaying your data")

I can get the content of the declared variable named 'contact_modify' at all line of code where I print it, but my POSTGRES SQL is not getting the content hence my EXCEPT part of the code is been execute. I am on POSGRES-9.3 and python 3.4 on 64 Windows10 Machine.

Answer 1

Try This:

  con.execute("""SELECT * FROM phone WHERE address_name ='%s';"""%(contact_modify))

If not work then do as @ Daniel Roseman said. remove try and except and see the actual error.

Answer 2

You should pass your variable manually, like this:

conn.execute("SELECT foo FROM table where bar = '%s'" % var) 

Also, you can use .format() method.