I try to insert data via python in my mysql database, it doesn't insert the data, I find my database to be empty but if I redo the same INSERT command, it rises a Duplicate Error.
Here is some example for my code:
connection = pymysql.connect(host='localhost',
user='user',
password='password',
db='literatur',
charset='utf8mb4',
cursorclass=pymysql.cursors.DictCursor)
with connection.cursor() as cursor:
sql = "INSERT into tf_data (tf_data_id, abstract) values (4, 'TEST')"
cursor.execute(sql)
connection.commit
It is somehow connecting the database (UPDATE commands actually work) and increasing the auto-increment of tf_data_id.
If I however do SELECT * FROM tf_data; mysql gives me >> empty set (0.00 s). How to find out what the problem is?
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 have an issue with inserting data into a database using the python package pyodbc and since I am pretty new to pyodbc & databases in general, I might lack some basic understanding.
I open a connection, and then I want the execute my query.
Actually, in this query I call a stored procedure (which I didn't write and I am not allowed to change!).
This procedure does "one or two" inserts. When I use pyodbc like this
conn = pyodbc.connect(connection_string)
with conn:
c = conn.cursor()
c.execute("{call input_procedure('some','parameters','to','insert')}")
OR
conn = pyodbc.connect(connection_string)
c = conn.cursor()
c.execute("{call input_procedure('some','parameters','to','insert')}")
conn.commit()
I get the following error message:
pyodbc.Error: ('HY000', "[HY000] [MySQL][ODBC 8.0(a) Driver]Commands out of sync; you can't run this command now (2014) (SQLEndTran(SQL_COMMIT))")
As far as I understood, this error message might be due to executing more than one insert within the called procedure. When I print the return of the execute command I become the following: (' ', )
When I instead close the cursor, before doing the commit, everything works fine. Like this:
conn = pyodbc.connect(connection_string)
c = conn.cursor()
c.execute("{call input_procedure('some','parameters','to','insert')}")
c.close()
conn.commit()
I really don't understand what's happening here.
Is there an explanation for this behaviour? Is closing the cursor before doing the commit save?
Thanks a lot for your help!
You seem to have encountered a quirk in MySQL Connector/ODBC's handling of result sets from a stored procedure. For this example procedure:
CREATE DEFINER=`root`#`localhost` PROCEDURE `input_procedure`(IN `p1` VARCHAR(50))
MODIFIES SQL DATA
BEGIN
INSERT INTO table1 (txt) VALUES (p1);
SELECT '' AS foo;
END
this Python code
crsr = cnxn.cursor()
crsr.execute("{call input_procedure('thing')}")
cnxn.commit()
throws the "Commands out of sync" error, whereas this code
crsr = cnxn.cursor()
crsr.execute("{call input_procedure('thing')}")
while crsr.nextset():
pass
cnxn.commit()
does not.
I am creating a Python app that will store my homework in a database (using PhpMyAdmin). Here comes my problem:
At this moment, I am sorting every input with an ID (1, 2, 3, 4...), a date (23/06/2018...), and a task (read one chapter of a book). Now I would like to sort them by the date because when I want to read what do I have to do. I would prefer to see what shall I do first, depending on when should I get it done. For example:
If I have two tasks: one 25/07/2018 and the other 11/07/2018, I would like to show the 11/07/2018 first, no matter if it was addead later than the 25/07/2018. I am using Python (3.6), pymysql and PhpMyAdmin to manage the database.
I have had an idea to get this working, maybe I could run a Python script every 2 hours, that sorts all the elements in the database, but I have no clue about how can I do it.
Now, I will show you the code that enters the values into a database and then it shows them all.
def dba():
connection = pymysql.connect(host='localhost',
user='root',
password='Adminhost123..',
db='deuresc',
charset='utf8mb4',
cursorclass=pymysql.cursors.DictCursor)
try:
with connection.cursor() as cursor:
# Create a new record
sql = "INSERT INTO `deures` (`data`, `tasca`) VALUES (%s, %s)"
cursor.execute(sql, (data, tasca))
# connection is not autocommit by default. So you must commit to save
# your changes.
connection.commit()
with connection.cursor() as cursor:
# Read a single record
sql = "SELECT * FROM `deures` WHERE `data`=%s"
cursor.execute(sql, (data,))
resultat = cursor.fetchone()
print('Has introduït: ' + str(resultat))
finally:
connection.close()
def dbb():
connection = pymysql.connect(host='localhost',
user='root',
password='Adminhost123..',
db='deuresc',
charset='utf8mb4',
cursorclass=pymysql.cursors.DictCursor)
try:
with connection.cursor() as cursor:
# Read a single record
sql = "SELECT * FROM `deures`"
cursor.execute(sql)
resultat = cursor.fetchall()
for i in resultat:
print(i)
finally:
connection.close()
Can someone help?
You don't sort the database. You sort the results of the query when you ask for data. So in your dbb function you should do:
SELECT * FROM `deures` ORDER BY `data`
assuming that data is the field with the date.