Develop Reference

How can we load data from a data frame to Azure SQL Server?

I am trying, for the first time ever, to send data from a data frame in Spyder to Azure SQL Server...I think it's called Synapse. I created a small table in the database and when I run the code below, I see the results I expect to see.
import pyodbc
server = 'ryan-server.database.windows.net'
database = 'ryan_sql_db'
username = 'UN'
password = 'PW'
driver= '{ODBC Driver 17 for SQL Server}'
with pyodbc.connect('DRIVER='+driver+';SERVER=tcp:'+server+';PORT=1433;DATABASE='+database+';UID='+username+';PWD='+ password) as conn:
with conn.cursor() as cursor:
cursor.execute("SELECT * From Order_Table")
row = cursor.fetchone()
while row:
print (str(row[0]) + " " + str(row[1]))
row = cursor.fetchone()
So, the connection is fine. I guess I am just stuck on the syntax to push a data frame to SQL Server in Azure. I tested the code below.
import pyodbc
server = 'ryan-server.database.windows.net'
database = 'ryan_sql_db'
username = 'UN'
password = 'PW'
driver= '{ODBC Driver 17 for SQL Server}'
conn = pyodbc.connect('DRIVER='+driver+';SERVER=tcp:'+server+';PORT=1433;DATABASE='+database+';UID='+username+';PWD='+ password)
all_data.to_sql('health', conn, if_exists='replace', index=True)
When I run that code, I get this error.
DatabaseError: Execution failed on sql 'SELECT name FROM sqlite_master WHERE type='table' AND name=?;': ('42S02', "[42S02] [Microsoft][ODBC Driver 17 for SQL Server][SQL Server]Invalid object name 'sqlite_master'. (208) (SQLExecDirectW); [42S02] [Microsoft][ODBC Driver 17 for SQL Server][SQL Server]Statement(s) could not be prepared. (8180)")

Try to do it by importing Pandas and pyodbc.
Below are few basic steps which we follow usually:
Connect to SQL Server.
Install all your python packages in your local.
Load the data into CSV.
Later you can use below Python script to load it from dataframe.
import pyodbc
import pandas as pd
df = pd.read_csv("c:\\user\\username\department.csv")
server = 'yourservername'
database = 'AdventureWorks'
username = 'username'
password = 'yourpassword'
cnxn = pyodbc.connect('DRIVER={SQL Server};SERVER='+server+';DATABASE='+database+';UID='+username+';PWD='+ password)
cursor = cnxn.cursor()
#Insert Dataframe into SQL Server:
for index, row in df.iterrows():
cursor.execute("INSERT INTO HumanResources.DepartmentTest (DepartmentID,Name,GroupName) values(?,?,?)", row.DepartmentID, row.Name, row.GroupName)
cnxn.commit()
cursor.close()
After completing the configs you can run below command to get the data from SQL:
SELECT count(*) from HumanResources.DepartmentTest;
Refer to this official doc for detailed explanation.

Connect python with SQL Server

I'm trying to load to the memory a table which is on a SQL Server database, but keep getting an error.
I coded:
import pyodbc
conn = pyodbc.connect('Driver={SQL Server};'
'Server=DESKTOP-VCIBA22\MS_SQL_SERVER;'
'Database=BikeStores;'
'Trusted_Connection=yes;')
cursor = conn.cursor()
cursor.execute('SELECT * FROM BikeStores.staffs')
and received the following error:
pyodbc.ProgrammingError: ('42S02', "[42S02] [Microsoft][ODBC SQL
Server Driver][SQL Server]Invalid object name 'BikeStores.staffs'.
(208) (SQLExecDirectW)")
Any ideas?
Thanks!

Python pyodbc 'execute only'

I am trying out the pyodbc to connect to a local MSSQL database with the code bellow:
import pyodbc
conn = pyodbc.connect('Driver={ODBC Driver 17 for SQL Server};'
'Server=localhost;'
'Database=SampleDb;'
'Trusted_Connection=yes;')
cursor = conn.cursor()
cursor.execute = ('SELECT * FROM SampleDb.dbo.flights')
for row in cursor:
print(row)
Getting the following error:
cursor.execute = ('SELECT * FROM SampleDb.dbo.flights')
AttributeError: 'pyodbc.Cursor' object attribute 'execute' is read-only

cursor.execute is a function, so you just need to call it and not to assign something to it. Try this:
cursor.execute('SELECT * FROM SampleDb.dbo.flights')
Sources:
pyodbc wiki

Unable to write to SQL Server even when using parameters

The SQL Server has these properties.
I want to write df to a SQL Server table but I get an error "table does not exist".
What am I doing wrong?
conn = pyodbc.connect('Driver={SQL Server};'
'Server=DESKTOP-FCBC9GE/NEW_INSTANCE;'
'Database=master;'
'Trusted_Connection=yes;')
cursor = conn.cursor()
cursor.execute('SELECT * FROM df')

Server does not exist or access denied

I have written below code to connect SQL Server Database from Visual Studio using Python:
import pyodbc
con = pyodbc.connect('Driver={SQL Server};Server=localhost;Database=ReportServerTempDB;Trusted_Connection=yes')
cur = con.cursor()
cur.execute("select [User], [datetime] FROM [ReportServerTempDB].[dbo].
[DBUpgradeHistory]")
for row in cur:
print (row.user + "," + row.datetime)
#print row[0] + "," + row[1]
cur.close()
con.close()
However, I'm getting an error like this:
Traceback (most recent call last):File "IronPythonApplication1.py",
line 2,in con = pyodbc.connect('Driver={SQL
Server};Server=localhost;Database=ReportServerTempDB;Trusted_Connection=yes')
pyodbc.Error: ('08001', '[08001] [Microsoft][ODBC SQL Server Driver]
[DBNETLIB]SQL Server does not exist or access denied. (17)
(SQLDriverConnect)')
Note: I have Windows Authentication to SQL Server, and I'm using VS 2015, and Python environment is IRON Python 64 bit 2.7
EDIT:
I changed driver as this: Driver={ODBC Driver 11 for SQL Server}
If I give like this in my code
for row in cur:
print (row.user)
getting a new kind of error.
Traceback (most recent call last):
File "IronPythonApplication1.py", line 6, in
for row in cur:
pyodbc.ProgrammingError: Attempt to use a closed cursor.
How to solve this?

I just changed it like this and its working:
import pyodbc
con = pyodbc.connect('Driver={ODBC Driver 11 for SQL Server};Server=localhost;Database=ReportServer;Trusted_Connection=yes')
cur = con.cursor()
cur.execute("select userid,username from Users")
for row in cur.fetchall():
print (row)