Tuesday, 15 October 2019

HP printer error - There was a problem connecting to the Server. Press Retry to connect again.

I had this error on my HP Photosmart and after much fruitless searching for the answer, reinstalling drivers and tweaking settings, discovered that as of 1 September 2016, for older models, web services are no longer supported. See the following link to verify [retrieved 15/10/2019]:


Thursday, 7 March 2019

MySQL Can't create/write to file (Errcode: 13)

I wanted to export a table from MySQL to CSV format, so I wrote the following MySQL to a file:

use mydb;

select *
from mytab
into outfile '/folder/myfile.csv'
fields terminated by ','
enclosed by '"'
lines terminated by '\n';

I then ran the following command line:

sudo mysql -u root < myExport.sql

This generated the following error:

ERROR 1 (HY000): Can't create/write to file '/folder/myfile.csv' (Errcode: 13)

After searching for answers to no avail, I then changed the MySQL code as follows:

select *
from mytab
into outfile 'myfile.csv'
fields terminated by ','
enclosed by '"'
lines terminated by '\n';

I then re-ran the above command line command and used the following Linux command to search the entire file system for the file:

find -name myfile.csv

It found the file in /var/lib/mysql/mydb.

Monday, 30 April 2018

How to Create a Fake HttpContext to Unit Test MVC Controller

Given: I needed to unit test that a response status code had been set within a controller action.
When: I didn't particularly want to refactor due to this being existing code.
Then: After experimenting unsuccessfully with creating various HttpContext classes, I found the simplest solution to be as follows within my test method:

var request = new HttpRequest("", "http://tempuri.org/", "");
var response = new HttpResponse(TextWriter.Null);
var httpContext = new HttpContextWrapper(new HttpContext(request, response));

_myController.ControllerContext = new ControllerContext(httpContext, new RouteData(), _myController);

var result = _myController.SomeAction(...some parameters...);

Assert.AreEqual(400, response.StatusCode);

Wednesday, 24 May 2017

SQL Shortcut Comparative "And" and "Or" Operator Conditions

In SQL Server Management Studio (SSMS), the following code returns "OK", suggesting that the evaluation conditions in SQL are shortcutted (ie. as soon as a condition is met, the code doesn't evaluate any subsequent conditions):

select case when 1=2 or 2=2 or 1/0 = 2 then 'ok' else 'no' end

Had all conditions been evaluated, a "divide by zero" error would have occurred.

I've not looked into whether this is standard ANSI SQL behaviour, but thought I'd share in case it is of use or interest to others.

Thursday, 19 February 2015

Permission denied when pushing to GitHub remote repository

When I tried to push code to GitHub recently, I got the following error despite running PuTTY and loading the SSH key that was associated with my GitHub account:

Permission denied (publickey).
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

It turned out that one of my settings in Git Extensions had reverted. I went into Settings, Settings, Ssh and selected the option against PuTTY. I was then able to push successfully.

Tuesday, 3 February 2015

List All Stored Procedures Within a SQL Database and Then Grant Execute on Them

It's been too long since I last blogged.

Thought I'd dust things off with this little snippet of T-SQL to list all stored procedures that exist within a specified SQL database:

USE YourDatabaseNameHere

AND LEFT(NAME,2) <> 'sp'
AND LEFT(NAME,2) <> 'dt'

This can be useful if you wish to grant execute permissions on these objects to your database login. For example, the following T-SQL will literally write out the commands you need to run in order to grant such execute permissions:

SELECT 'GRANT EXECUTE ON ' + NAME + ' TO YourDatabaseLoginNameHere'
AND LEFT(NAME,2) <> 'sp'
AND LEFT(NAME,2) <> 'dt'

You can take the output from the above, paste into a query window and run:

GRANT EXECUTE ON MyStoredProc TO YourDatabaseLoginNameHere
GRANT EXECUTE ON AnotherStoredProc TO YourDatabaseLoginNameHere
GRANT EXECUTE ON AndAnotherStoredProc TO YourDatabaseLoginNameHere

Friday, 19 July 2013

RESTORE cannot process database 'X' because it is in use by this session

When running a restore database query, I got the above error in SQL Management Studio. This was due to having the database 'X' selected in the dropdown list of databases, as suggested by the second part of the error message, which stated "It is recommended that the master database be used when performing this operation."

I changed the dropdown to another database 'Y' and was able to re-run the query without error.