I am running a script that stores different datasets to a MySQL database. This works so far, but only sequentially. e.g.:
# write table1
replaceTable(con,tbl="table1",dframe=dframe1)
# write table2
replaceTable(con,tbl="table2",dframe=dframe2)
If I select both (I use StatET / Eclipse) and run the selection, I get an error:
Error in function (classes, fdef, mtable) :
unable to find an inherited method for function "dbWriteTable",
for signature "MySQLConnection", "data.frame", "data.frame".
I guess this has to do with the fact that my con is still busy or so when the second request is started. When I run the script line after line it just works fine. Hence I wonder, how can I tell R to wait til the first request is ready and then go ahead ? How can I make R scripts interactive (just console like plot examples - no tcl/tk).
EDIT:
require(RMySQL)
replaceTable <- function(con,tbl,dframe){
if(dbExistsTable(con,tbl)){
dbRemoveTable(con,tbl)
dbWriteTable(con,tbl,dframe)
cat("Existing database table updated / overwritten.")
}
else {
dbWriteTable(con,tbl,dframe)
cat("New database table created")
}
}
dbWriteTable has two important arguments:
overwrite: a logical specifying whether to overwrite an existing table
or not. Its default is ‘FALSE’.
append: a logical specifying whether to append to an existing table
in the DBMS. Its default is ‘FALSE’.
For past project I have successfully achieve appending, overwriting, creating, ... of tables with proper combinations of these.
Related
I am using python to automatically populate a MySQL DB. The script that populates the DB (/path/to/pythonScript.py very long) is actually called by another python script (example below) works fine and I have added a few statements that prevent me from inserting duplicated entries.
When I try to insert a duplicated entry with the script /path/to/pythonScript.py I get (as expected)
ProgrammingError: 1061 (42000): Duplicate key name 'unique_index'
In order to deal with that, I want to write a try except statement while calling the /path/to/pythonScript.py script, as shown below:
import mysql.connector
from mysql.connector.errors import ProgrammingError
# Here I have already successfully connected to the DB, and populated it
try:
get_ipython().system("ipython /path/to/pythonScript.py") # this is the script that populates the DB. It does not allow the insertion of duplicated entries
except ProgrammingError:
print("a warning message informing that I am trying to insert a duplicated entry")
When I call the script for the first time, everything goes well (after all, the DB was empty). But then when I call the script for the second time (i.e. when I attempt to insert duplicated entries) I am still getting the same error ProgrammingError: 1061 (42000): Duplicate key name 'unique_index'
I have found this documentation page where they show examples on how to handle errors, though there is no example specifically on the ProgrammingError. In this other documentation page there is one example on the ProgrammingError, though they skipped the imports section and I am afraid I am missing something by the import (note that I don't get any error when I call from mysql.connector.errors import ProgrammingError)?
You are running the other script as a distinct process. Exceptions only exist within the current process - FWIW, you could be running a shell script or a C-coded binary app instead, it would be just the same.
I kindly suggest you momentarily ditch IPython and take a couple days doing the full official Python tutorial, paying particular attention to the parts about functions and modules. Then you may want to rewrite your first script to make it a proper module with proper functions (I assume from your question and example code it's currently a plain script with everything at the top-level - but I may be wrong of course ;) ), then rewrite your calling script to import functions from the first one and call them.
Also note that that ProgrammingError can happen for a whole lot of other reasons than a duplicate key, so you MUST check the exception's code to find out which exact error happened.
I am trying to save an Access query with the following statement.
INSERT INTO FOO( DES_MOTIVO, DES_TIPO, DES_SUBTIPO,
AGRUPACIÓN, SEMANA, CuentaDeCOD_ACCION_CLIENTE )
IN 'C:\Users\BAR\Desktop\03. Hola\DB STATIC INTERACCIONES MES.accdb'
I am getting an error when saving the query, saying the path is incorrect. Testing the path, i found out that the culprit is the period+whitespace in "03. Hola". Deleting the whitespace fixed the issue and the query saves properly.
Is there a way to escape the period so that access accepts the save path with period + whitespace?
Thank you in advance,
Nega.
Apparently this is not possible with SQL or VBA code.
Fun fact: You can do it in the query designer by setting the Destination database setting of the query properties. Set your path, the query can be saved and executed (and it works!).
But switch to SQL view and try to save: you get the "invalid bracketing" error. Same when trying to set the SQL from VBA.
And the DestinationDB property that the help file mentions isn't available via code. It seems to be derived from the IN clause.
So your database will have to moved to a better path. Or, if it's single user, copy to temp path, run the INSERT, copy back.
See also: https://support.microsoft.com/en-us/kb/132184
Try adding quotes around the path:
"INSERT INTO FOO( DES_MOTIVO, DES_TIPO, DES_SUBTIPO, AGRUPACIÓN, SEMANA, CuentaDeCOD_ACCION_CLIENTE ) IN '""C:\Users\BAR\Desktop\03. Hola\DB STATIC INTERACCIONES MES.accdb""'"
But why do you maintain such weird folder names as "03. Hola"?
Indeed on the Desktop, you should be able to create a simpler folder name.
I am using syslog-ng to parse some logs that I am receiving via a csv-parser. However, I want to achieve insert operations that are a bit more complex than the conventional insert using the "destination" option in syslog-ng. Currently, my destination into MYSQL from my syslog-ng conf file looks like this:
destination d_sql_test
{
sql(
type(mysql)
host('<host>')
username('<user>')
password('<pass>')
database('<db_name>')
table('test')
columns('col1')
values('${val1}')
);
};
However, this simply just inserts the contents of val1 into the column col1. I want to be able to specify my insert "logic" as shown in the example in this question.
I am unsure as to where to actually do this, and if it is even supported by syslog-ng
I think you can do this if you can somehow make the decision within syslog-ng.
You could try to use an in-list() filter to check if the username is already listed in a file. If it is not then, you can send the log into the mysql destination, and also to another destination (possibly a program() destination) that updates the file containing the list of users, and reloads the syslog-ng to update the inlist filter.
You can write a syslog-ng template-function in Python that implements the logic somehow, and for example sets a macro to 1 in the message if it should be sent to the database. Then you can use a filter for this macro in your log path with the mysql destination.
Or if you can write a separate destination that does the work in Python: Writing syslog-ng destinations in Python
Also, you might want to post this question on the syslog-ng mailing list, where the developers notice it more easily.
I stumbled upon the following:
def save_formset(self, request, form, formset, change):
instances = formset.save(commit=False)
bargain_id = 0
total_price = Decimal(0)
for instance in instances:
if isinstance(instance, BargainProduct):
total_price += instance.quantity * instance.product.price
bargain_id = instance.id
instance.save()
updateTotal = Bargain.objects.get(id=bargain_id)
updateTotal.total_price = total_price - updateTotal.discount_price
updateTotal.save()
This code is working for me on my local MySQL setup, however, on my live test enviroment running on SQLite3* I get the "Bargain matching query does not exist." error..
I am figuring this is due to a different hierarchy of saving the instances on SQLite.. however it seems they run(and should) act the same..?
*I cannot recompile MySQL with python support on my liveserver atm so thats a no go
Looking at the code, if you have no instances coming out of the formset.save(), bargain_id will be 0 when it gets down to the Bargain.objects.get(id=bargain_id) line, since it will skip over the for loop. If it is 0, I'm guessing it will fail with the error you are seeing.
You might want to check to see if the values are getting stored correctly in the database during your formset.save() and it is returning something back to instances.
This line is giving the error:
updateTotal = Bargain.objects.get(id=bargain_id)
which most probably is because of this line:
instances = formset.save(commit=False)
Did you define a save() method for the formset? Because it doesn't seen to have one built-in. You save it by accessing what formset.cleaned_data returns as the django docs say.
edit: I correct myself, it actually has a save() method based on this page.
I've been looking at this same issue. It is saving the data to the database, and the formset is filled. The problem is that the save on instances = formset.save(commit=False) doesn't return a value. When I look at the built-in save method, it should give back the saved data.
Another weird thing about this, is that it seems to work on my friends MySQL backend, but not on his SQLITE3 backend. Next to that it doesn't work on my MySQL backend.
Local loop returns these print outs (on MySQL).. on sqlite3 it fails with a does not excist on the query
('Formset: ', <django.forms.formsets.BargainProductFormFormSet object at 0x101fe3790>)
('Instances: ', [<BargainProduct: BargainProduct object>])
[18/Apr/2011 14:46:20] "POST /admin/shop/deal/add/ HTTP/1.1" 302 0
Just wondering if anyone could give a working example of using the erlang-mysql module (http://code.google.com/p/erlang-mysql-driver/).
I am new to erlang and I am trying to replace some old scripts with a few erlang batch processes. I am able to connect to the DB and even complete a query, but I am not sure how I use the results. Here is what I currently have:
-include("../include/mysql.hrl").
...
mysql:start_link(p1, "IP-ADDRESS", "erlang", "PASSWORD", "DATABASE"),
Result1 = mysql:fetch(p1, <<"SELECT * FROM users">>),
io:format("Result1: ~p~n", [Result1]),
...
I also have a prepared statement that I am also using to get just one row (if it exists) and it would be helpful to know how to access the results on that as well
This is described in the source code of mysql.erl:
Your result will be {data, MySQLRes}.
FieldInfo = mysql:get_result_field_info(MysqlRes), where FieldInfo is a list of {Table, Field, Length, Name} tuples.
AllRows = mysql:get_result_rows(MysqlRes), where AllRows is a list of lists, each representing a row.
you should check the count of rows,
then execute:
eg:
RowLen = erlang:length(Row),
if
RowLen > 0 ->
{success};
true ->
{failed, "Row is null"}
end.
After trying to use the ODBC module that comes with Erlang/OTP, and running into problems, I recommend the mysql/otp driver. I replaced ODBC with it in just a few hrs and it works fine.
They have good documentation so I will not add examples here.