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Setting Default value for column in MS access using sql query in Python [duplicate]

I'm trying to add a column to an MS Access database table using pyodbc and Python 3.5.
Using the expression
self.cursor.execute("ALTER TABLE data ADD COLUMN testColumn TEXT(10)")
works fine, but when I try to add a default value (DEFAULT "no"), it throws a Syntax error. I've tried multiple combinations, but no luck.
Any help is much appreciated!
Cheers

Sadly, the Access ODBC driver simply does not support the DEFAULT clause for a column in CREATE/ALTER TABLE statements. The ODBC driver and OLEDB provider for Access have diverged somewhat in their DDL support, so unfortunately we can get inconsistent results for the same DDL statement as illustrated by the following VBScript code using ADO:
OLEDB works fine ...
Option Explicit
Dim conn
Set conn = CreateObject("ADODB.Connection")
Dim connStr
connStr = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\Users\Public\mdbTest.mdb"
conn.Open connStr
On Error Resume Next
conn.Execute "DROP TABLE Cheeses"
On Error GoTo 0
conn.Execute "CREATE TABLE Cheeses (Id LONG PRIMARY KEY, CheeseName TEXT(50) DEFAULT 'Cheddar')"
conn.Execute "INSERT INTO Cheeses (Id) VALUES (1)"
Dim rst
Set rst = CreateObject("ADODB.Recordset")
rst.Open "SELECT CheeseName FROM Cheeses WHERE Id = 1", conn
If rst("CheeseName").Value = "Cheddar" Then
WScript.Echo "Success"
End If
conn.Close
... but if we change the connection string to use ODBC ...
connStr = "Driver={Microsoft Access Driver (*.mdb, *.accdb)};Dbq=C:\Users\Public\mdbTest.mdb"
... then our attempt to execute the CREATE TABLE statement fails with
Microsoft OLE DB Provider for ODBC Drivers: [Microsoft][ODBC Microsoft Access Driver] Syntax error in CREATE TABLE statement.
TL;DR - You can't use the DEFAULT clause in a CREATE/ALTER TABLE statement under pyodbc.

can't see table created by pyodbc in ms access

I am accessing a MS Access Database in Python 3.6 using pyodbc library. I can read a table, no problems. The I created a simple table (Employee). I inserted records. I was able to fetch the records too by reading the table, no problems.
I also listed the tables in the MS Access DB. Employee table shows in the list.
But when I open up the MS Access Database, I do not find the table. I changed MS Access DB to show hidden and system objects. Employee table doesn't show up.
What am I doing wrong?
Thanks
Here is the code:
import pyodbc
db_file = r'''C:\TickData2018\StooqDataAnalysis.accdb'''
user = 'admin'
password = ''
odbc_conn_str = 'DRIVER={Microsoft Access Driver (*.accdb)};DBQ=%s;UID=%s;PWD=%s' %\
(db_file, user, password)
# Or, for newer versions of the Access drivers:
odbc_conn_str = 'DRIVER={Microsoft Access Driver (*.mdb, *.accdb)};DBQ=%s;UID=%s;PWD=%s' %\
(db_file, user, password)
conn = pyodbc.connect(odbc_conn_str)
print("connection made")
c = conn.cursor()
c.execute("SELECT * FROM 5MtsBaseForAnalysisSorted")
list1 = c.fetchmany(2)
print(list1[0][0])
print(list1[0][1])
print(list1[0][2])
try:
c.execute("""CREATE TABLE employee(
first text,
last text,
pay integer
);""")
except Exception as e:
print(e)
conn.commit
c.execute("INSERT INTO employee VALUES ('Krishna', 'Sundar', 50000)")
c.execute("INSERT INTO employee VALUES ('Divya', 'Sundar', 70000)")
c.execute("INSERT INTO employee VALUES ('Panka', 'Sundar', 70000)")
conn.commit
c.execute("SELECT * FROM employee")
print(c.fetchall())
c.tables()
rows = c.fetchall()
for row in rows:
print(row)
c.close()
del c
conn.close()

This is a general Python object model where you need to call the actual function and not its bounded name. Specifically, your commit lines are not correct where
conn.commit
Should be with open/close parentheses:
conn.commit()
Another way to see the difference is by reviewing the object's type:
type(conn.commit)
# <built-in method commit of pyodbc.Connection object at 0x000000000B772E40>
type(conn.commit())
# NoneType
I did reproduce your issue with exact code and adding parentheses resolved the issue.

An additional solution to manually committing is to set autocommit = True when the connection instance is created.
Eg:
conn = pyodbc.connect(odbc_conn_str, autocommit = True)

Print Data from MySQL Database to Console from Python

I'm using Visual Studio 2017 with a Python Console environment. I have a MySQL database set up which I can connect to successfully. I can also Insert data into the DB. Now I'm trying to display/fetch data from it.
I connect fine, and it seems I'm fetching data from my database, but nothing is actually printing to the console. I want to be able to fetch and display data, but nothing is displaying at all.
How do I actually display the data I select?
#importing module Like Namespace in .Net
import pypyodbc
#creating connection Object which will contain SQL Server Connection
connection = pypyodbc.connect('Driver={SQL Server};Server=DESKTOP-NJR6F8V\SQLEXPRESS;Data Source=DESKTOP-NJR6F8V\SQLEXPRESS;Integrated Security=True;Connect Timeout=30;Encrypt=False;TrustServerCertificate=True;ApplicationIntent=ReadWrite;MultiSubnetFailover=False')
cursor = connection.cursor()
SQLCommand = ("SELECT ID FROM MyAI_DB.dbo.WordDefinitions WHERE ID > 117000")
#Processing Query
cursor.execute(SQLCommand)
#Commiting any pending transaction to the database.
connection.commit()
#closing connection
#connection.close()

I figured it out. I failed to include the right Print statement. Which was:
print(cursor.fetchone())
I also had the connection.commit statement in the wrong place (it was inserted even executing the Print statement). The final code that worked was this:
#importing module Like Namespace in .Net
import pypyodbc
#creating connection Object which will contain SQL Server Connection
connection = pypyodbc.connect('Driver={SQL Server};Server=DESKTOP-NJR6F8V\SQLEXPRESS;Data Source=DESKTOP-NJR6F8V\SQLEXPRESS;Integrated Security=True;Connect Timeout=30;Encrypt=False;TrustServerCertificate=True;ApplicationIntent=ReadWrite;MultiSubnetFailover=False')
cursor = connection.cursor()
SQLCommand = ("SELECT * FROM MyAI_DB.dbo.WordDefinitions")
#Processing Query
cursor.execute(SQLCommand)
#Commiting any pending transaction to the database.
print(cursor.fetchone())
connection.commit()
#closing connection
#connection.close()

python code CREATE table in ms SQL server [duplicate]

I am trying to create tables in a MS Access DB with python using pyodbc but when I run my script no tables are created and no errors are given. My code:
#!/usr/bin/env python
import pyodbc
con = pyodbc.connect(r'DRIVER={Microsoft Access Driver (*.mdb, *.accdb)};DBQ=Z:\Data\Instruments\testDB.accdb; Provider=MSDASQL;')
cur = con.cursor()
string = "CREATE TABLE TestTable(symbol varchar(15), leverage double, shares integer, price double)"
cur.execute(string)
What could be wrong?

You need to commit the transaction:
import pyodbc
con = pyodbc.connect(r'DRIVER={Microsoft Access Driver (*.mdb, *.accdb)};DBQ=Z:\Data\Instruments\testDB.accdb; Provider=MSDASQL;')
cur = con.cursor()
string = "CREATE TABLE TestTable(symbol varchar(15), leverage double, shares integer, price double)"
cur.execute(string)
con.commit()

Additional solutions that do not require a manual commit are:
Set autocommit = True when the connection instance is created.
Eg:
con = pyodbc.connect(your_connection_string, autocommit = True)
OR
Use a with statement that, according to Python Database connection Close, will commit anything before the connection is deleted at the end of the with block.
Eg:
with pyodbc.connect(your_connection_string) as con:
CREATE_TABLE_CODE_WITHOUT_COMMIT
UNRELATED_CODE

SQL Server temp table not available in pyodbc code

I'm running a series of complex sql queries in python and it involves temp tables. My auto-commit method doesn't seem to be working to retrieve the data from the temp table. The code snippet I'm using below and this is the output I'm getting:
testQuery="""
Select top 10 *
INTO #Temp1
FROM Table1 t1
JOIN Table2 t2
on t1.key=t2.key
"""
cnxn=pyodbc.connect(r'DRIVER={SQL Server Native Client 11.0};SERVER=server;DATABASE=DB;UID=UID;PWD=PWD')
cnxn.autocommit=True
cursor=cnxn.cursor()
cursor.execute(testQuery)
cursor.execute("""Select top 10 * from #Temp1""")
<pyodbc.Cursor at 0x8f78930>
cnxn=pyodbc.connect(r'DRIVER={SQL Server Native Client 11.0};SERVER=server;DATABASE=DB;UID=UID;PWD=PWD')
cnxn.autocommit=True
cursor=cnxn.cursor()
cursor.execute(testQuery)
cursor.execute("""Select top 10 * from #Temp1""")

Even though this question has a "solution", i.e., using global temp table instead of a local temp table, future readers might benefit from understanding why the problem happened in the first place.
A temporary table is automatically dropped when the last connection using said table is closed. The difference between a local temp table (#Temp1) and a global temp table (##Temp1) is that the local temp table is only visible to the connection that created it, while an existing global temp table is available to any connection.
So the following code using a local temp table will fail ...
conn = pyodbc.connect(conn_str, autocommit=True)
crsr = conn.cursor()
sql = """\
SELECT 1 AS foo, 2 AS bar INTO #Temp1
"""
crsr.execute(sql)
conn = pyodbc.connect(conn_str, autocommit=True)
crsr = conn.cursor()
sql = """\
SELECT foo, bar FROM #Temp1
"""
crsr.execute(sql)
row = crsr.fetchone()
print(row)
... while the exact same code using a global temp table will succeed ...
conn = pyodbc.connect(conn_str, autocommit=True)
crsr = conn.cursor()
sql = """\
SELECT 1 AS foo, 2 AS bar INTO ##Temp1
"""
crsr.execute(sql)
conn = pyodbc.connect(conn_str, autocommit=True)
crsr = conn.cursor()
sql = """\
SELECT foo, bar FROM ##Temp1
"""
crsr.execute(sql)
row = crsr.fetchone()
print(row)
... because the second pyodbc.connect call opens a separate second connection to the SQL Server without closing the first one.
The second connection cannot see the local temp table created by the first connection. Note that the local temp table still exists because the first connection was never closed, but the second connection cannot see it.
However, the second connection can see the global temp table because the first connection was never closed and therefore the global temp table continued to exist.
This type of behaviour has implications for ORMs and other mechanisms that may implicitly open and close connections to the server for each SQL statement that it executes.

I asked a colleague about this live and his suggestions worked. So I went and changed the testQuery to create a global temp table instead of a local (##Temp1 instead of #Temp1). And went to sql server to test whether the temp table was actually being created-it was. So I isolated that the problem was the second cursor.execute statement. I modified the code to use pandas read_sql_query instead and it all worked out! Below is the code I used:
testQuery="""
Select top 10 *
INTO ##Temp1
FROM Table1 t1
JOIN Table2 t2
on t1.key=t2.key
"""
cnxn=pyodbc.connect(r'DRIVER={SQL Server Native Client 11.0};SERVER=server;DATABASE=DB;UID=UID;PWD=PWD')
cnxn.autocommit=True
cursor=cnxn.cursor()
cursor.execute(testQuery)
cnxn.commit()
query1="Select top 10 * from ##Temp1"
data1=pd.read_sql_query(query1, cnxn)
data1[:10]

Best way to go about this is to start your SQL query with:
"SET NOCOUNT ON"
This will output the desired data

The SET NOCOUNT ON is what worked for me.
execute Method () - JDBC Driver for SQL Server | Microsoft Docs
Return Value
true, if the statement returns a result set.
false, if it returns an update count or no result.
If you want a result set, then setting SET NOCOUNT ON s the setting you need in your statements.