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Im trying to conennect to an sql database that its already created an that its located on a server. How can I connect to this database using python. Ive tried using java but I cant seem to get working either.
Well depending on what sql database you are using you can pip install pymssql for microsoft sql (mssql), psycopg2 for postgres (psql) or mysqldb for mysql databases
Here are a few examples of using it
Microsoft sql
import pymssql
conn = pymssql.connect(server=server, user=user, password=password, database=db)
cursor = conn.cursor()
cursor.execute("SELECT COUNT(MemberID) as count FROM Members WHERE id = 1")
row = cursor.fetchone()
conn.close()
print(row)
Postgres
import psycopg2
conn = psycopg2.connect(database=db, user=user, password=password, host=host, port="5432")
cursor = conn.cursor()
cursor.execute('SELECT COUNT(MemberID) as count FROM Members WHERE id = 1')
row = cursor.fetchone()
conn.close()
print(row)
mysql
import MySQLdb
conn = MySQLdb.connect(host=host, user=user, passwd=passwd, db=db)
cursor = conn.cursor()
cursor.execute('SELECT COUNT(MemberID) as count FROM Members WHERE id = 1')
row = cursor.fetchone()
conn.close()
print(row)
Related
I am currently developing a program in python that interacts with multiple database. I am using pyodbc to connect, and execute queries. One of the database is an azure database. I noticed sometimes the sent data is not updated in the database although the program run successfully and no error was thrown. Is there any practices that i should follow to make sure this doesn't happen or is this related to my code or db connection issue? I am a beginner. Would appreciate everyone's help thank you!
Also is the .commit() line should be run after every sql run?
The program should be updating a row of data in the database based on a condition, this particular query sometimes doesn't take effect, but no error was thrown. I also executed multiple queries after that, no issue was found for the next queries. It is successfully executed.
the query is a simple query which is
UPDATE DraftVReg SET VRStatus = 'Potential Duplicate Found' WHERE RowID = ?
I tried to reproduce your scenario on my end and was able to update the SQL row in the Azure SQL DB with Pyodbc module.
Yes, Its very necessary to use
conn.commit
to commit your changes inside a database after you perform operations such as Update or Insert inside Azure SQL DB programmatically.
1) Fetch Data with Select statement.
I was able to fetch the Table’s data successfully with Select * from ‘Tablename’ query inside pyodbc code before I try UPDATE statement.
import pyodbc
conn = pyodbc.connect('DRIVER={ODBC Driver 17 for SQL Server};''SERVER=tcp:sqlservernamesql.database.windows.net,1433;''DATABASE=databasename; UID=siliconuser;PWD=Password;')
#conn.commit()
cursor = conn.cursor()
cursor.execute('Select * FROM StudentReviews')
#conn.commit()
for i in cursor:
print(i)
cursor.close()
conn.close()
Result:-
2) UPDATE the rows require conn.commit()
Code :-
import pyodbc
conn = pyodbc.connect('DRIVER={ODBC Driver 17 for SQL Server};''SERVER=tcp:siliconserversql.database.windows.net,1433;''DATABASE=silicondb; UID=userid; PWD=Password;')
cursor = conn.cursor()
#cursor.execute('Select * FROM StudentReviews')
cursor.execute("UPDATE StudentReviews SET ReviewTime = ('7') WHERE ReviewText = ('SQL DB')")
conn.commit()
cursor.close()
conn.close()
Result:-
Update statement Executed successfully and the Table Row was updated in Azure SQL, Refer Below :-
3) With autocommit=true
Thank you #Gord thompson for the comment and suggestion!
Code :-
import pyodbc
conn = pyodbc.connect('DRIVER={ODBC Driver 17 for SQL Server};''SERVER=tcp:siliconserversql.database.windows.net,1433;''DATABASE=silicondb; UID=username; PWD=Password;', autocommit=True)
#conn.commit()
cursor = conn.cursor()
cursor.execute("UPDATE StudentReviews SET ReviewTime = ('8') WHERE ReviewText = ('SQL DB')")
cursor.close()
conn.close()
Results :- With autocommit=true, You do not need to add conn.commit everytime you update the SQL DB.
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 want to connect to MySql database using Python through PythonAnywhere, without creating a Flask/Django application.
I have seemingly managed to connect through MySQLdb, using the code below, but I do not receive a response when I run the code. Any solutions?
import MySQLdb
db = MySQLdb.connect(
host = "myuser.mysql.pythonanywhere-services.com",
user = "myuser",
passwd = XXX,
db = "myuser$db_name"
)
cursor = db.cursor()
cursor.execute("SELECT * FROM table_name")
for x in cursor:
print(x)
cursor.close()
db.close()
You retrieve all rows in the table, without error.
cursor.execute("SELECT * FROM table_name")
for x in cursor:
print(x)
Yet you see no output. This is normal for a table that contains zero rows.
Consider doing one or more INSERTs, and a COMMIT,
prior to the query.
I am trying to update my mariadb table via python code .While compile the query nothing happen in my database. please check below code and let me know where i made mistake in update function
import mariadb
connection= mariadb.connect(user="user1", database="db1", host="ippp" ,password="pass")
cursor= connection.cursor()
cursor.execute("UPDATE product_options_combinations SET quantity=5944 WHERE item_code ='31628'")
cursor.close()
connection.close()
Hello here I have a clean code example for you. How to update it.
import pymysql
# Create a connection object
# IP address of the MySQL database server
Host = "localhost"
# User name of the database server
User = "user"
# Password for the database user
Password = ""
database = "GFG"
conn = pymysql.connect(host=Host, user=User, password=Password, database)
# Create a cursor object
cur = conn.cursor()
query = f"UPDATE PRODUCT SET price = 1400 WHERE PRODUCT_TYPE = 'broadband'"
cur.execute(query)
#To commit the changes
conn.commit()
conn.close()
You just need to add connection.commit() to your code, but I recommend you use a parametrized SQL preferably with a list of tuples,more of which might be added if needed, along with cursor.executemany() as being more performant for DML statements such as
import mariadb
connection= mariadb.connect(user="user1",
password="pass",
host="ippp",
port=3306,
database="db1")
cursor= connection.cursor()
dml="""
UPDATE product_options_combinations
SET quantity=%s
WHERE item_code =%s
"""
val=[
(5944,'31628')
]
cursor.executemany(dml,val)
connection.commit()
cursor.close()
connection.close()
Are you sure that the connection is working properly?
Have you tried to implement a try and catch routine to print mariadb errors?
Something like this:
# Connect to MariaDB Platform
import mariadb
try:
conn = mariadb.connect(
user="user",
password="password",
host="xx.xx.xx.xx",
port=3306,
database="db_name"
)
except mariadb.Error as e:
print(f"Error connecting to MariaDB Platform: {e}")
sys.exit(1)
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()