Develop Reference

pyodbc not updating table

I query a table then loop through it to Update another table.
The console Prints shows correct data.
Not sure how to debug the cursor.execute for the UPDATE query.
It is not updating on the table. It's not a permission issue. If I run update command on my SQL workbench it works fine.
cursor = conn.cursor()
cursor.execute("Select Account_Name FROM dsf_CS_WebAppView")
for row in cursor.fetchall():
try:
cursor.execute("Select fullpath FROM customerdesignmap WHERE
fullpath LIKE '%{}%'".format(row.Account_Name))
rows = cursor.fetchall()
print(len(cursor.fetchall()))
if len(rows) > 0:
for rowb in rows:
print(rowb.fullpath)
print(row.Account_Name)
if len(row.Account_Name) > 2:
cursor.execute("UPDATE customerdesignmap SET householdname = {}, msid = {} WHERE fullpath LIKE '{}'".format(row.Account_Name, row.UniqueProjectNumber, rowb.fullpath))
conn.commit()
except:
pass

Consider a pure SQL solution as SQL Server supports UPDATE and JOIN across multiple tables. This avoids the nested loops, cursor calls, and string formatting of SQL commands.
UPDATE m
SET m.householdname = v.Account_Name,
m.msid = v.UniqueProjectNumber
FROM customerdesignmap m
JOIN dsf_CS_WebAppView v
ON m.fullpath LIKE CONCAT('%', v.Account_Name, '%')
In Python, run above in a single cursor.execute() with commit() call.
cursor.execute('''my SQL Query''')
conn.commit()

cx_oracle python iteration

I have my python script which reads an excel column row by row and returns all rows str(values).
I want to write another script which will allow put these values to sql db. I've already written connect method:
def db_connect():
adr = 'some_addr'
uid = 'some_uid'
pwd = 'pwd'
port = port
dsn_tns = cx_Oracle.makedsn(adr, port, SID)
db = cx_Oracle.connect('username', 'pass', dsn_tns)
cur = db.cursor()
cur.execute('update TABLE set ROW = 666 where ANOTHER_ROW is null')
db.commit()
This method does an update but it sets 666 for ALL rows. How to do it by kind of iteration in sql? For example, first row of output == 1, second == 23, third == 888.

If I understand correctly what you are trying to do here it should be done in two phases. First select all rows for update (based on chosen condition), then you can iteratively update each of these rows.
It cannot be done in single query (or on only single condition that does not change through a number of queries), because SQL works on sets, that's why each time your query is executed you are updating whole table, and in the end only getting result of the last query.

You can use the "rownum" expression, as in:
cur.execute("update TABLE set ROW = rownum where ANOTHER_ROW is null")
This will start with the value 1 and increment up by one for each row updated.
If you want more control over the value to set, you can also do the following in PL/SQL (untested):
cur.execute("""
declare
t_NewValue number;
cursor c_Data is
select ROW, ANOTHER_ROW
from TABLE
where ANOTHER_ROW is null
for update;
begin
t_NewValue := 1;
for row in c_Data loop
update TABLE set ROW = t_NewValue
where current of c_Data;
t_NewValue := t_NewValue + 1;
end loop;
end;""")
This gives you the most control. You can use whatever logic you require to control what the new value should be.

Please take a look at another method which is writing to excel:
adr = 'some_addr'
uid = 'some_uid'
pwd = 'pwd'
port = port
dsn_tns = cx_Oracle.makedsn(adr, port, SID)
db = cx_Oracle.connect('username', 'pass', dsn_tns)
cur = db.cursor()
cells = excel.read_from_cell()
indices_and_statuses = []
stat = execute_script(some_js)
for req_id in cells:
indices_and_statuses.append((cells.index(req_id), stat))
cur.execute("""update TABLE set ROW ="""+"'"+req_id+"'"+"""where ANOTHER_ROW is null""")
db.commit()
db.close()
And in this code when you put print(req_id) in this FOR statement, you will see that req_id is changing. But in DB only the last req_id is saved.

Python script to move data from a SQL server db to an oracle db keeps giving 'ORA-01036: illegal variable name/number'

So I am using python to pull data from a sql server with a simple select that grabs 15 columns. The data looks like this
2016-06-01 05:45:06.003,5270,240,1,1,0,5000,1,null,null,7801009661561,0,null,null,null
The columns on the oracle table are all number except for the first column which is date. The sizes are all correct.
After I get all the data i run it through this little function to get rid of the pyodbc.row types.
def BuildBindList(recordsToWrite):
closingRecords = []
for rec in recordsToWrite:
closingRecords.append((rec[0], rec[1], rec[2], rec[3], rec[4], rec[5], rec[6], rec[7], rec[7], rec[8], rec[9], rec[10], rec[11], rec[12], rec[13], rec[14]))
return closingRecords
I get a list of tuples.
Then to write to the oracle table I wrote this function that takes in the list of tuples.
def write_to_table(recordsToWrite):
SQL = '''INSERT INTO ####### (DATETIME, ID, TZ, DOMAINID, EVENTNAME, REASONCODE, TARGETID, STATE, KEY, PERIPHERALKEY, RECOVERYKEY, DIRECTION, ROUTERDAY, ROUTERCKEY, ROUTERNUMBER)
VALUES(:1, :2, :3, :4, :5, :6, :7, :8, :9, :10, :11, :12, :13, :14, :15)'''
try:
trgtcrsr.prepare(SQL)
except cx_Oracle.DatabaseError, exception:
print ('Failed to prepare cursor')
print Exception(exception)
exit (1)
try:
trgtcrsr.executemany(None, recordsToWrite)
except cx_Oracle.DatabaseError, exception:
print ('Failed to insert rows')
print Exception(exception)
exit (1)
target_connection .commit()
target_connection .close()
I make the oracle connection like this
try:
cnn = cx_Oracle.connect(user="####", password = "####", dsn = "####")
trgtcrsr = cnn.cursor()
print "Connected to Oracle"
except Exception as e:
print e
raise RuntimeError("Could not connect to Oracle")
The connection works fine. But when the line trgtcrsr.executemany(None, recordsToWrite) is executed it gives me a 'ORA-01036: illegal variable name/number' error
I have another script that uses the same method of writing a list of tuples to an oracle table with the trgtcrsr.prepare(SQL)/trgtcrsr.executemany(None, recordsToWrite) method and it works fine (granted its oracle to oracle) writing to oracle so I am not sure why I keep getting this error. I have tried changing data types and googling the error but cant find anything similar.
Any ideas?

rec[7] appears twice in the function BuildBindList().
I'm guessing this will cause the insert to fail as you passed it 16 columns to instantiate 15 bind variables in the insert statement.

**#PYTHON SCRIPT TO COPY DATA FROM ORACLE TO SQL SERVER**
import cx_Oracle
import pyodbc
#Server Variables
orServer = '10.xxx.x.xxx'
orPort = 'xxxx'
orService = 'MYSERV'
orUser = 'ORMYUSER'
orPassword = 'orpassword'
sqlServer = 'SQLSERVER'
sqlDatabase = 'MYDB'
#SQL Server Connection
sqlConn = pyodbc.connect('Driver={SQL Server};'
'Server='+sqlServer+';'
'Database='+sqlDatabase+';'
'Trusted_Connection=yes;')
sqlCursor = sqlConn.cursor()
#Oracle Connection
dsn_tns = cx_Oracle.makedsn(orServer, orPort, service_name= orService )
orConn = cx_Oracle.connect(user= orUser, password= orPassword, dsn=dsn_tns)
orCursor = orConn.cursor()
#Get data from Oracle Server
orCursor.execute("""SELECT ID
,NAME
,SEX
,ADDRESS
PHONE
FROM DetailsTable"""
)
orColumns =['ID',
'NAME',
'SEX',
'ADDRESS',
'PHONE']
#Creating Strings for insert statement to load data into SQL Server
cValues = str(orColumns).replace("[","(").replace("]",")").replace("'","")
x = len(orColumns)
i = 0
ab = []
while i < x:
i = i+ 1
ab.append("?")
values = str(ab).replace("[","(").replace("]",")").replace("'","")
#Load data to SQL server
sqlCursor.executemany("INSERT INTO [MYDB].[dbo].[DetailsTable]"+ cValues+ " VALUES "+ values ,orCursor)
sqlConn.commit()
sqlConn.close()
orConn.close()

Update statement not working in python?

I've written a simple python program, which get Data form database successfully. but unable to update table in DB.
When executing update statement it's get stuck and nothing happen, no any exception.
My code is as follows. Any idea whyis this ?
from java.sql import DriverManager
def updateDB():
url = "jdbc:oracle:thin:#192.1.1.1:1521:auid"
uname = "dbtstj1"
pword = "dbtstj321"
conn = None
stmt = None
try:
conn = DriverManager.getConnection(url,uname,pword)
stmt = conn.createStatement()
rs = stmt.executeQuery("select PKG_NAME from PkgData")
while rs.next():
print rs.getString(1)
pkgName = "'Test Pkg Name'"
pkgID = "'T1234'"
updateQuary = "UPDATE PkgData SET PKG_NAME =%s WHERE PKG_ID =%s" %(pkgName, pkgID)
stmt.execute(updateQuary)
except Exception , e:
print 'Error:', e[0]
finally:
if stmt is not None:
stmt.close()
if conn is not None:
conn.close()
updateDB()

you need to commit your changes to the database:
stmt.execute(updateQuary)
conn.commit()

These type of issues can be happen when query request datatype and required datatype is difference.
It seems to be there was a mismatch with database's datatype and your query. Can you recheck with database's datatype with your query.
For Ex: PKG_ID =%s can be another data type in database as digit or etc...

TypeError: 'NoneType' object is not iterable

I need to process mysql data one row at a time and i have selected all rows put them in a tuple but i get the error above.
what does this mean and how do I go about it?

Provide some code.
You probably call some function that should update database, but the function does not return any data (like cursor.execute()). And code:
data = cursor.execute()
Makes data a None object (of NoneType). But without code it's hard to point you to the exact cause of your error.

It means that the object you are trying to iterate is actually None; maybe the query produced no results?
Could you please post a code sample?

The function you used to select all rows returned None. This "probably" (because you did not provide code, I am only assuming) means that the SQL query did not return any values.

Try using the cursor.rowcount variable after you call cursor.execute(). (this code will not work because I don't know what module you are using).
db = mysqlmodule.connect("a connection string")
curs = dbo.cursor()
curs.execute("select top 10 * from tablename where fieldA > 100")
for i in range(curs.rowcount):
row = curs.fetchone()
print row
Alternatively, you can do this (if you know you want ever result returned):
db = mysqlmodule.connect("a connection string")
curs = dbo.cursor()
curs.execute("select top 10 * from tablename where fieldA > 100")
results = curs.fetchall()
if results:
for r in results:
print r

This error means that you are attempting to loop over a None object. This is like trying to loop over a Null array in C/C++. As Abgan, orsogufo, Dan mentioned, this is probably because the query did not return anything. I suggest that you check your query/databse connection.
A simple code fragment to reproduce this error is:
x = None
for each i in x:
#Do Something
pass

This may occur when I try to let 'usrsor.fetchone' execute twice. Like this:
import sqlite3
db_filename = 'test.db'
with sqlite3.connect(db_filename) as conn:
cursor = conn.cursor()
cursor.execute("""
insert into test_table (id, username, password)
values ('user_id', 'myname', 'passwd')
""")
cursor.execute("""
select username, password from test_table where id = 'user_id'
""")
if cursor.fetchone() is not None:
username, password = cursor.fetchone()
print username, password
I don't know much about the reason. But I modified it with try and except, like this:
import sqlite3
db_filename = 'test.db'
with sqlite3.connect(db_filename) as conn:
cursor = conn.cursor()
cursor.execute("""
insert into test_table (id, username, password)
values ('user_id', 'myname', 'passwd')
""")
cursor.execute("""
select username, password from test_table where id = 'user_id'
""")
try:
username, password = cursor.fetchone()
print username, password
except:
pass
I guess the cursor.fetchone() can't execute twice, because the cursor will be None when execute it first time.

I know it's an old question but I thought I'd add one more possibility. I was getting this error when calling a stored procedure, and adding SET NOCOUNT ON at the top of the stored procedure solved it. The issue is that earlier selects that are not the final select for the procedure make it look like you've got empty row sets.

Try to append you query result to a list, and than you can access it. Something like this:
try:
cursor = con.cursor()
getDataQuery = 'SELECT * FROM everything'
cursor.execute(getDataQuery)
result = cursor.fetchall()
except Exception as e:
print "There was an error while getting the values: %s" % e
raise
resultList = []
for r in result:
resultList.append(r)
Now you have a list that is iterable.