I am trying to connect to Oracle through Python and trying to execute a few DDL & DML statements. Please help how it can be done
a simple query
import cx_Oracle
con = cx_Oracle.connect('pythonhol/welcome#127.0.0.1/orcl')
cur = con.cursor()
cur.execute('select * from departments order by department_id')
for result in cur:
print result
cur.close()
con.close()
You can do something like this:
import cx_Oracle
connection = cx_Oracle.connect("username", "password", "ip of your server"/"database name")
cursor = connection.cursor()
cursor.execute("select * from table_name")
for row in cursor:
print(row)
connection.close()
Related
I am creating a program that uses VS Code and MySQL Workbench 8.0 together. I am stuck and do not know how to connect the two software together
I also have to be able to upload records into a table that is stored in MySQL Workbench from the Python program that uses variables.
Please tell me if their are any details missing.
Thank you.
For connection:
I have researched on Google and have been unable to find an answer. I have found that I have to install certain packages and use the connect method. However, I do not know the parameters of the connect function.
For uploading data into table:
I have found that I have to create a cursor to somehow upload the data to the table, but am unsusre of the full details.
There are many packages in python that can connect to the mysql database, here we take pymysql as an example.
Install pymysql
pip install PyMySQL
I have already installed, so the prompt package already exists.
Sample code, query and insert data
import pymysql
con = pymysql.Connect(
host='localhost',
port=3306,
user='root',
password='123456',
db='test',
charset='utf8'
)
cur = con.cursor()
sql1 = 'select * from student'
cur.execute(sql1)
data = cur.fetchall()
cur.close()
con.close()
for i in data:
print(str(i))
Add an insert data statement, and re-query after inserting data.
import pymysql
con = pymysql.Connect(
host='localhost',
port=3306,
user='root',
password='123456',
db='test',
charset='utf8'
)
cur = con.cursor()
sql2 = 'insert into student values("002","jerry","W");'
cur.execute(sql2)
sql1 = 'select * from student'
cur.execute(sql1)
data = cur.fetchall()
con.commit()
cur.close()
con.close()
for i in data:
print(str(i))
I have already searched for several solutions here and tried to get a working code. Everything works except for the where query.
In the where query I search for the highest value (numeric). However, this does not really work...
Here is my code and the structure of the MySQL database.
Thanks!
import pymysql
conn = pymysql.connect(host='localhost', unix_socket='', user='root', passwd='pw', db='database')
cur = conn.cursor()
cur.execute("SELECT * FROM dose")
for r in cur:
curr = conn.cursor()
sql = """UPDATE dose
SET status = "printed"
WHERE id = SELECT GREATEST (status) FROM dose (status);"""
# print(sql)
try:
# Execute the SQL command
curr.execute(sql)
# Commit your changes in the database
conn.commit()
except:
# Rollback in case there is any error
conn.rollback()
curr.close()
cur.close()
conn.close()
My SQL Database
You have a lot of things wrong in your code.
You don´t use the results of your first select query, and the only thing that you do is iterate over the results to execute an UPDATE
Your update query is wrong
You should change it to:
import pymysql
conn = pymysql.connect(host='localhost', unix_socket='', user='root', passwd='pw', db='database')
curr = conn.cursor()
sql = """UPDATE dose
SET status = 'printed'
WHERE id = (SELECT max(status) FROM dose) """
try:
# Execute the SQL command
curr.execute(sql)
# Commit your changes in the database
conn.commit()
except:
# Rollback in case there is any error
conn.rollback()
curr.close()
conn.close()
I'm connecting to a postgres database in Heroku and trying to create a table. I run the code below but no new table shows up in the database.
import psycopg2
conn = psycopg2.connect(DATABASE_URL, sslmode='require')
create_table = (""" CREATE TABLE test_table (account_address__c varchar); """)
cur = conn.cursor()
cur.execute(create_table)
conn.close()
Can you help?
Thank you!
I forgot to add
conn.commit()
.
cur = conn.cursor()
cur.execute(create_table)
conn.commit()
conn.close()
I'm new to Python and I wanted to ask you for help.
I want to put the data of a view in SQL Server into a table of my database in MySQL, when I try to give the following error:
Execution failed on sql: SELECT name FROM sqlite_master WHERE
type='table' AND name=?; not all arguments converted during string
formatting unable to rollback
Using Python version 3.7
Below is the code I use:
import pymysql.cursors
import pyodbc
import pandas as pd
# SQL Server Connection
connection = pyodbc.connect("DSN=SQLServer") #autocommit=True
try:
with connection.cursor() as cursor:
result = "SELECT * FROM dw.dbo.vW_sale"
df = pd.read_sql_query("SELECT * FROM dw.dbo.vW_sale", connection)
cursor.execute(result)
table = cursor.fetchall()
print(table)
finally:
connection.close()
# MySQL connection
cnx = pymysql.connect(host='test',
user='test',
password='test',
db='dw')
try:
with cnx.cursor() as cursor:
mysql = "select *from ft_sale_test"
cursor.execute(mysql)
result = cursor.fetchall()
#print(result)
finally:
cnx.close()
# using if_exists to handle the table that already exists
The error happens right here
df.to_sql(con=cnx, name= 'ft_sale_test', if_exists= 'replace')
I use pypyodbc to read data from an ms sql server.
I am not sure if the cursor should be closed after any query or just once at the end and I could not find anything in the doc.
Example:
curs = con.cursor()
for id in id_list:
curs.execute ('Select * from XXX where id = {}'.format (id))
curs.fetchall ()
# Write the data into the target...
# curs.close() ???
curs.close()
Is this correct?
thanks
The with keyword is what you are looking for
with sqlite3.connect("db.db") as DB:
cursor = DB.cursor()
#...perform sql
# connection automatically closes