Syndicate content

value

Can I create an INDEX to accelerate a SELECT MIN(IF(...)) in MySQL?

I have a table with a few columns, two of which are integers, one of which can be NULL in which case the other integer is to be used in my query.

CREATE TABLE my_table (col1 INTEGER NOT NULL, col2 INTEGER);

If `col2` is NULL, then use `col1`. As is, there is how my query looks like:

SELECT MIN(IF(col2, col2, col1)) AS smallest FROM my_table LIMIT 1;

In other words, I need to get the row with the smallest integer, but if one column is NULL, I want to use the other column value.

On a very small sample, the query is still very fast, but the real version is not unlikely to have thousands ...

Display a line number in a table (i.e. subform of records)

I was ask by a customer to add line numbers to each entry in a table shown in an invoice.

The concept is pretty simple, but really, how do you do that properly in MS-Access?

Microsoft actually has a solution (see link below) and it comes down to writing a function that counts the number of items from that item's current position to the beginning of the table (i.e. going backward). It works, it is just really bad if you have very large invoices since it will tend to slow down as you start getting many items.

There is the function, we can see the counting in the do until near the end ...

Large scale Linux console

As I am working on our Snap! C++ CMS, I created a set of virtual systems to test the compilation on "clean" system (yeah! my main computers has all sorts of things that I don't even know about...)

In those virtual system, I only install the basic server and then do a sudo apt-get install of anything else the server needs to get compiled. This includes libraries such as libmagic, boost, and Qt and some tools like xmllint. This is pretty cool, but when working in a console, and that console is very small, it makes it a bit difficult, so I looked into making it big.

For this ...

Debug and/or Release specific command line option in cmake

Today I ran in a problem with cmake which was to very simply select /MT instead of /MD for a small set of projects. The problem is that so far this feature was at least on a per directory basis. Since the exact same directory is used to build the dynamic (DLL) and static (.lib) libraries, having two directories is not exactly an option here.

set ( CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} /MT" )
set ( CMAKE_C_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} /MT" )
set ( CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_RELEASE} /MTd" )
set ( CMAKE_C_FLAGS_DEBUG ...

Setting up an array of JavaScript functions in jQuery

Today I worked a bit with jQuery to create an advanced form. Advanced just because it is tabbed and appears in a pop-up, nothing too major really. Maybe later I'll add some tests to validate the data being entered before someone can submit the form...

In any event, I ran in a problem which was to create a set of click callback functions (event handlers) and each of which should make use of a different index. So... I have 4 tabs and each one has a number: 1, 2, 3, and 4.

Say I call each one of these numbers #tab1, #tab2, #tab3, and #tab4. Now I want to create a click function on each one ...

get_defined_vars() PHP function

Once in a while, I need to get the complete list of all the variables available in a PHP piece of code.

This is done with the get_defined_vars() PHP function. It's very simple, it returns an array of name / value pairs. You can then print that value using print_r() or var_dump().

That's it!

C printf(3) for int, long and long long that works every time

Of Note: This only applies to C99, not C++.

I learned something quite interesting today and wanted to keep a note of it.

Whenever I use a printf() with a format such as %ld and try to compile my code on "many" different platforms, I often get warnings on another one.

The fact is that an int, a long, a long long, an int32_t, int64_t all use a different combination depending on your platform and whether you're running in 32 or 64 bit.

So, the answer to this problem are the #define found in the inttypes.h header file:

PRId8
PRId16
PRId32
PRId64

These entries are used after

Closing a window from Flash

I had a little project which requirements was an Adobe Flash animation that calls a JavaScript function to close a browser window.

With the newest version of Internet Explorer, it will first ask you whether you want to let the script close your window... that's a problem when you'd like that process to be smooth (i.e. without user interaction.)

Negative constant ... was passed to a negative sink

Today, as I was working with Coverity, I got this one message...

Negative constant passed to a negative sink.

Although I understood the meaning, I thought that this message was very confusing, How about:

Unexpected negative value in parameter #<position>

Syndicate content Syndicate content

Diverse Realty

Diverse Realty Team

Want a New Home?
Want to Sell Your House?

Call Alex at
+1 (916)
220 6482

Alexis Wilke, Realtor
Salesperson
Lic. # 02024063

Cory Marcus, Broker
Lic. # 01079165

     

Terms of Site Index

Find the page/content you are looking for with our index.