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Python looping to obtain different dataframes from a SQL database

I'm trying to connect to an SQL database and, within a loop, create separate dataframes for each different instance of Id, containing all the data related to that Id. I've tried a number of ways, without any success so far. I'm pretty new to all of this, so I'm probably making some rookie mistakes.
Attempt 1:
import pandas as pd
import pyodbc
conn = pyodbc.connect('Driver={SQL Server};'
'Server=Server_name;'
'Database=Database;'
'UID=Username;'
'PWD=password;'
'Trusted_Connection=yes;')
Name = ['HR','ZA','PR','FW']
for x in Name:
SQL = '''
SELECT *
FROM Database
WHERE Id = {x}'''.format(x = x)
cursor = conn.cursor()
cursor.execute(SQL)
df = pd.read_sql_query(SQL)
On this code, I get an 'invalid column name' programming error on the first Name 'HL'.
Attempt 2:
import pandas as pd
import pyodbc
conn = pyodbc.connect('Driver={SQL Server};'
'Server=Server_name;'
'Database=Database;'
'UID=Username;'
'PWD=password;'
'Trusted_Connection=yes;')
SQL = '''
SELECT *
FROM Database
conn.autocommit = True
cursor.execute(SQL)
for [Id] in cursor:
df = pd.Dataframe(SQL,conn)
On this code, I get a 'ValueError: too many values to unpack (expected 1)' - on the for statement.
I want to put a lot more code in the for loop so I need it to be set up to work through each Id. I hope that makes sense. Any guidance would be greatly appreciated. Thanks
UPDATE:
Thanks for all comments/answers. For some reason I just couldn't get it to work in either of the formats above so I took it back to where I started from now I understand how to include the syntax for the loop variable. The following now works:
import pandas as pd
import pyodbc
conn = pyodbc.connect('Driver={SQL Server};'
'Server=Server_name;'
'Database=Database;'
'UID=Username;'
'PWD=password;'
'Trusted_Connection=yes;')
Name = ['HR','ZA','PR','FW']
for x in Name:
SQL = pd.read_sql_query(
'''
SELECT *
FROM Database_table
WHERE Id = '{x}'
'''.format(x = x), conn)
df = pd.DataFrame(SQL)

I think that if you try a variation on your first attempt like:
for x in Name:
SQL = '''
SELECT *
FROM Database
WHERE Id = ?'''
cursor = conn.cursor()
cursor.execute(SQL)
df = pd.read_sql_query(SQL, params={x})
It should probably work :)

Postgres connection in python

I am struggling to establish a connection inside data iteration. Means I am running a select query to postgres and iterating the return data. after some transformation I am writing it to another table. But it is not working. Sample python code is below.
conn = pgconn(------)
cursor = pgconn.Cursor()
query1 = "select * from table"
query2 = "select * from table2 where Id=(%s);"
cursor.execute(query1)
result = query1.fetchall()
for row in result:
If row.a == 2:
cursor.execute(query2, [row.time])
In the above python code I can't able to extract the data by running query2 and passing query1 result as a parameter. It seems cursor is blocked by the query1 so query2 execution is not happening. Please some one help in this issue.

First of all you can write a join statement to do this and can get the data easily
select * from table join table2 where table2.id == table.time
Also why this is not working maybe because the cursor object is getting override inside the for loop and thus the query results get changed.

Use RealDictCursor, and correct the syntax on your inside call to execute():
import psycopg2
import psycopg2.extras
conn = pgconn(------)
cursor = conn.cursor(cursor_factory=psycopg2.extras.RealDictCursor)
query1 = "select * from table"
query2 = "select * from table2 where Id=(%s);"
cursor.execute(query1)
result = query1.fetchall()
for row in result:
If row.a == 2:
cursor.execute(query2, (row['time'],))

1. install psycopg2 and psycopg2.extras. ( pip install)
Then set up your Postgres Connection like:
def Postgres_init(self):
try:
conn = psycopg2.connect(host=os.environ['SD_POSTGRES_SERVER'],
user=os.environ['SD_POSTGRES_USER'],
password=os.environ['SD_POSTGRES_PASSWORD'],
port=os.environ['SD_POSTGRES_PORT'],
database=os.environ['SD_POSTGRES_DATABASE'])
logging.info("Connected to PostgreSQL")
except (Exception, psycopg2.Error) as error:
logging.info(error)
2. Connect your Cursor with the defined connection
cursor = conn.cursor()
3. Execute your query:
cursor.execute("""SELECT COUNT (column1) from tablename WHERE column2 =%s""", (
Value,)) # Check if already exists
result = cursor.fetchone()
Now the value is stored in the "result" variable. Now you can execute the next query like:
cursor.execute("""
INSERT INTO tablename2
(column1, column2, column3)
VALUES
(%s, %s, %s)
ON CONFLICT(column1) DO UPDATE
SET
column2=excluded.column2,
column3=excluded.column3;
""", (result, column2, column3)
)
Now the result of query 1 is stored in the second table in the first column.
Now you can close your connection:
conn.close()

How do I issue a SQL query using pyodbc that involves python variables as the parameters?

I am writing a program that searches a database and inputs the data into a excel file based on user selection from two calendars (on the GUI). I have a start and end date, I am passing those variables as parameters into a function for my SQL query.
How do I format the SQL query to select the values from the given dates?
Here is my code so far,
def load_database(startDate, endDate):
conn = pyodbc.connect('Driver={ODBC Driver 17 for SQL Server};'
'Server=DESKTOP-KVR7GNJ\SQLBULKROLL;'
'Database=db_MasterRoll;'
'UID=sa;'
'PWD=Z28#6420d')
wb = Workbook()
ws = wb.active
ws.title = "Star Ledger"
cursor = conn.cursor()
cursor.execute('SELECT ID, BarCode, DateTm, EntryDoor FROM dbo.tab_Rolls WHERE (DateTm >= #startDate) AND (DateTm <= #endDate)')
a button invokes this code by running the function "call_db_code()":
def call_db_code():
firstDate = start_dateCalendar.selection_get()
print(firstDate)
finalDate = end_dateCalendar.selection_get()
print(finalDate)
load_database(firstDate, finalDate)

Use ? as placeholders in the query, and provide a tuple of values to substitute for them.
cursor.execute('SELECT ID, BarCode, DateTm, EntryDoor FROM dbo.tab_Rolls WHERE (DateTm >= ?) AND (DateTm <= ?)', (startDate, endDate))
See the examples in the cursor.execute() documentation.

Python and MySQL - fetchall() doesn't show any result

I have a problem getting the query results from my Python-Code. The connection to the database seems to work, but i always get the error:
"InterfaceError: No result set to fetch from."
Can somebody help me with my problem? Thank you!!!
cnx = mysql.connector.connect(
host="127.0.0.1" ,
user="root" ,
passwd="*****",
db="testdb"
)
cursor = cnx.cursor()
query = ("Select * from employee ;")
cursor.execute(query)
row = cursor.fetchall()

If your problem is still not solved, you can consider replacing the python mysql driver package and use pymysql.
You can write code like this
#!/usr/bin/python
import pymysql
db = pymysql.connect(host="localhost", # your host, usually localhost
user="test", # your username
passwd="test", # your password
db="test") # name of the data base
# you must create a Cursor object. It will let
# you execute all the queries you need
cur = db.cursor()
query = ("SELECT * FROM employee")
# Use all the SQL you like
cur.execute(query)
# print all the first cell of all the rows
for row in cur.fetchall():
print(row[0])
db.close()
This should be able to find the result you want

add this to your code
for i in row:
print(i)
you did not print anything which is why that's not working
this will print each row in separate line

first try to print(row),if it fails try to execute using the for the loop,remove the semicolon in the select query statement
cursor = connection.cursor()
rows = cursor.execute('SELECT * FROM [DBname].[dbo].TableName where update_status is null ').fetchall()
for row in rows:
ds = row[0]
state = row[1]
here row[0] represent the first columnname in the database
& row[1] represent the second columnname in the database & so on

Retrieve data from sql server database using Python

I am trying to execute the following script. but I don't get neither the desired results nor a error message ,and I can't figure out where I'm doing wrong.
import pyodbc
cnxn = pyodbc.connect("Driver={SQL Server Native Client 11.0};"
"Server=mySRVERNAME;"
"Database=MYDB;"
"uid=sa;pwd=MYPWD;"
"Trusted_Connection=yes;")
cursor = cnxn.cursor()
cursor.execute('select DISTINCT firstname,lastname,coalesce(middlename,\' \') as middlename from Person.Person')
for row in cursor:
print('row = %r' % (row,))
any ideas ? any help is appreciated :)

You have to use a fetch method along with cursor. For Example
for row in cursor.fetchall():
print('row = %r' % (row,))
EDIT :
The fetchall function returns all remaining rows in a list.
If there are no rows, an empty list is returned.
If there are a lot of rows, *this will use a lot of memory.*
Unread rows are stored by the database driver in a compact format and are often sent in batches from the database server.
Reading in only the rows you need at one time will save a lot of memory.
If we are going to process the rows one at a time, we can use the cursor itself as an interator
Moreover we can simplify it since cursor.execute() always returns a cursor :
for row in cursor.execute("select bla, anotherbla from blabla"):
print row.bla, row.anotherbla
Documentation

I found this information useful to retrieve data from SQL database to python as a data frame.
import pandas as pd
import pymssql
con = pymssql.connect(server='use-et-aiml-cloudforte-aiops- db.database.windows.net',user='login_username',password='login_password',database='database_name')
cursor = con.cursor()
query = "SELECT * FROM <TABLE_NAME>"
cursor.execute(query)
df = pd.read_sql(query, con)
con.close()
df

import mysql.connector as mc
connection creation
conn = mc.connect(host='localhost', user='root', passwd='password')
print(conn)
#create cursor object
cur = conn.cursor()
print(cur)
cur.execute('show databases')
for i in cur:
print(i)
query = "Select * from employee_performance.employ_mod_recent"
emp_data = pd.read_sql(query, conn)
emp_data