Question

I dont see why it’s not working. I have created several databases and tables and obviously no problem. But I am stuck with this table which is created from django data model. To clarify what I have done, created new database and table from mysql console and try to insert from python and working. But, this one is strange for me.

class Experiment(models.Model):
    user = models.CharField(max_length=25)
    filetype = models.CharField(max_length=10)
    createddate= models.DateField()
    uploaddate = models.DateField()
    time = models.CharField(max_length=20)
    size = models.CharField(max_length=20)
    located= models.CharField(max_length=50)

Here is view in mysql console

mysql> describe pmass_experiment;
+-------------+-------------+------+-----+---------+----------------+
| Field       | Type        | Null | Key | Default | Extra          |
+-------------+-------------+------+-----+---------+----------------+
| id          | int(11)     | NO   | PRI | NULL    | auto_increment |
| user        | varchar(25) | NO   |     | NULL    |                |
| filetype    | varchar(10) | NO   |     | NULL    |                |
| createddate | date        | NO   |     | NULL    |                |
| uploaddate  | date        | NO   |     | NULL    |                |
| time        | varchar(20) | NO   |     | NULL    |                |
| size        | varchar(20) | NO   |     | NULL    |                |
| located     | varchar(50) | NO   |     | NULL    |                |
+-------------+-------------+------+-----+---------+----------------+
8 rows in set (0.01 sec)

Above pmass_experiment table is created by django ORM after python manage.py syncdb

Now I am trying to insert data into pmass_experiment through python MySQLdb

import MySQLdb
import datetime,time
import sys

conn = MySQLdb.connect(
    host="localhost",
    user="root",
    passwd="root",
    db="experiment")

cursor = conn.cursor()
user='tchand'
ftype='mzml'
size='10MB'
located='c:\'
date= datetime.date.today()
time = str(datetime.datetime.now())[10:19]

#Insert into database
sql = """INSERT INTO pmass_experiment (user,filetype,createddate,uploaddate,time,size,located)
    VALUES (user, ftype, date, date, time, size, located)"""
try:
   # Execute the SQL command
   cursor.execute(sql)
   # Commit your changes in the database
   conn.commit()
except:
   # Rollback in case there is any error
   conn.rollback()
# disconnect from server
conn.close()

But, unfortunately nothing is inserting. I am guessing it’s may be due to primary_key (id) in table which is not incrementing automatically.

mysql> select * from pmass_experiment;
Empty set (0.00 sec)

can you simply point out my mistake?

Thanks

Answer 1

sql = """INSERT INTO pmass_experiment (user,filetype,createddate,uploaddate,time,size,located)
    VALUES (user, ftype, date, date, time, size, located)"""

Parametrize your sql and pass in the values as the second argument to cursor.execute:

sql = """INSERT INTO pmass_experiment (user,filetype,createddate,uploaddate,time,size,located)
         VALUES (%s, %s, %s, %s, %s, %s, %s)"""
try:
   # Execute the SQL command
   cursor.execute(sql,(user, ftype, date, date, time, size, located))
   # Commit your changes in the database
   conn.commit()
except Exception as err:
   # logger.error(err) 
   # Rollback in case there is any error
   conn.rollback()

It is a good habit to always parametrize your sql since this will help prevent sql injection.

The original sql

INSERT INTO pmass_experiment (user,filetype,createddate,uploaddate,time,size,located)
    VALUES (user, ftype, date, date, time, size, located)

seems to be valid. An experiment in the mysql shell shows it inserts a row of NULL values:

mysql> insert into foo (first,last,value) values (first,last,value);
Query OK, 1 row affected (0.00 sec)
mysql> select * from foo order by id desc;
+-----+-------+------+-------+
| id  | first | last | value |
+-----+-------+------+-------+
| 802 | NULL  | NULL |  NULL | 
+-----+-------+------+-------+
1 row in set (0.00 sec)

So I’m not sure why your are not seeing any rows committed to the database table.

Nevertheless, the original sql is probably not doing what you intend.