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)
Related
When I'm using pymysql to perform operations on MySQL database, it seems that all the operations are temporary and only visible to the pymysql connection, which means I can only see the changes through cur.execute('select * from qiushi') and once I cur.close() and conn.close() and log back in using pymysql, everything seems unchanged.
However, when I'm looking at the incremental id numbers, it does increased, but I can't see the rows that were inserted from pymysql connection. It seems that they were automatically deleted?!
Some of my code is here:
import pymysql
try:
conn = pymysql.connect(host='127.0.0.1',port=3306,user='pymysql',passwd='pymysql',charset='utf8')
cur = conn.cursor()
#cur.execute('CREATE TABLE qiushi (id INT NOT NULL AUTO_INCREMENT, content_id BIGINT(10) NOT NULL, content VARCHAR(1000), created TIMESTAMP DEFAULT CURRENT_TIMESTAMP, PRIMARY KEY(id));')
#cur.execute('DESCRIBE content')
#cur.fetchall()
cur.execute('USE qiushibaike')
for _ in range(0,len(content_ids)):
cur.execute("INSERT INTO qiushi (content,content_id) VALUES (\"%s\",%d)"%(jokes[_],int(content_ids[_])))
finally:
cur.close()
conn.close()
I solved the problem by myself...
Because the config is automatically committed, so after each SQL sentence we should commit the changes.
Approach 1:
add cur.commit() after the cur.execute()
Approach 2:
edit the connection config, add autocommit=True
I am making a python GUI that will look up the the status of a helpdesk ticket in a MySQL database. I connected python to an existing MySQL database with SQLAlchemy using the code below.
conn = mysql.connector.connect(user='root',
password='stuff',host='127.0.0.1',
database='mydb')
c = conn.cursor()
I only need access to one of the columns, ticket_id, in a table called tickets. Basically I want to do this:
SELECT ticket_status FROM tickets WHERE ticket_id = 123;
What would be simplest way to do this?
The following code should work at fetching a single value. If you realize later you need to fetch more than one value you can change fetchone() to fetchall()
try:
sql = '''
SELECT ticket_status FROM tickets WHERE ticket_id = 123
'''
c.execute(sql)
result = c.fetchone()
except Exception as e:
raise Exception(e)
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
Basically I'm trying to update Column1_mbgl field data in Table1, all based in MS Access database. The script gets executed without any errors, but when the table is checked no update occurred. I have tried two options as shown in the code without any success. The second option is the SQL code generated directly from MS Access query. Can anybody suggest what I'm missing in the code?
#import pypyodbc
import pyodbc
# MS ACCESS DB CONNECTION
pyodbc.lowercase = False
conn = pyodbc.connect(
r"Driver={Microsoft Access Driver (*.mdb, *.accdb)};" +
r"Dbq=C:\temp\DB_access.accdb;")
# OPEN CURSOR AND EXECUTE SQL
cur = conn.cursor()
# Option 1 - no error and no update
cur.execute("UPDATE Table1 SET Column1_mbGL = Column2_mbGL-0.3 WHERE ((Column3_name='PZ01') AND (DateTime Between #6/14/2016 14:0:0# AND #6/16/2016 12:0:0#) AND (TYPE='LOG'))");
# Option 2 - no error and no update
#cur.execute("UPDATE Table1 SET Table1.Column1_mbGL = [Table1]![Column2_mbGL]-0.3 WHERE (((Table1.Column3_name)='PZ01') AND ((Table1.DateTime) Between #6/14/2016 14:0:0# And #6/16/2016 12:0:0#) AND ((Table1.TYPE)='LOG'))");
cur.close()
conn.close()
You forgot to conn.commit() after executing your UPDATE query. The Python database API specifies that connections open with "autocommit" off by default, so an explicit commit is needed.
I am trying to add all words of a text file into a column such that one row has one word. my code is as :
import MySQLdb
conn = MySQLdb.connect (host = "localhost",user = "root", db = "pcorpora")
c = conn.cursor()
file = open('C:\Users\Admin\Desktop\english.txt', 'r')
words = list(file.read())
i=0
for value in words:
c.execute("""INSERT INTO tenglish (`english words`) VALUES (%s)""" % (words[i]) i=i+1)`
The code run without error but table is still empty.
You should use commit
c.execute("""INSERT INTO tenglish (`english words`) VALUES (%s)""" % (value))
con.commit()
This method sends a COMMIT statement to the MySQL server, committing
the current transaction. Since by default Connector/Python does not
autocommit, it is important to call this method after every
transaction that modifies data for tables that use transactional
storage engines.