Learning SQL development can seem like an overwhelming task at first. However, mastering just a few key points will help ease your way through 80 percent of the day-to-day challenges when writing stored procedures and solving common problems. Here are three important SQL development factors to keep in mind:

Outer Joins
One of the most crucial things to understand in SQL server are joins. Joins are a way to retrieve data from two or more tables based on logical relationships between them. Joins dictate how Microsoft SQL Server ought to use data from one table to select the rows in another table.

In my experience inner joins are intuitive while outer joins can present additional hours of grief by overlooking associations in the other table(s). The outer join is the key to answering questions about what the database does not have. For example, if you need to make a query to display all the students who are without report-cards, you’ll need a left join to get all students coupled with a “where clause” to return the ones who have nulls for their report card table columns in the results.

Many talented Java script programmers have muddled through the SQL Server by deficient coding around the inner join. As a result, their queries can take five hours to run, whereas, properly written left joins, can take only two seconds to run.

Aggregation
Grouping results comes up in SQL a lot more than you might think. Knowing how to write a query when answering questions such as, “What’s the average grade for each teacher’s student list?” is invaluable. This kind of question cannot be answered with a single table or solely by joins.  You’ll often find you need to use joins in conjunction with group by statements. Always write the raw query first and then look at the results. Next, you have to figure out the best way to group them, rewrite your select clause and add a group by clause in the end.

Digging Through Data
I find this is the most lacking skill in many programmers. In fact, many otherwise-talented programmers holding Master’s Degrees fail to get jobs because they couldn’t analyze rows of data objectively during interviews. It’s just something that’s not taught but is crucial to get under you belt. Why? Eventually, some query is not going to perform as you may expect. And, the only way to find discrepancies is to look at rows of data, identify what join isn’t finding a match or where bad data is throwing things into chaos. Get familiar with how joins actually work, even if you have to manually walk through the logic of a large stored procedure’s tree of joins. It’s boring and time-consuming but absolutely necessary.

Take the time to master the core skills that will make you a successful SQL Programmer and avoid queries that run for five hours!

The python keyword global is used in a function to distinguish a local representation of a variable with the same name. 

glbvar = 0

def setglbvar():
    global glbvar # include this declaration so that updates to glbvar are NOT LOCAL to this function
    glbvar = 1

def printglbvar():
    print glbvar     # No need for global declaration to read value of globvar

setglbvar()
printglbvar()       # Prints 1

Technology has continued to evolve in ways that few would have been able to imagine. This has allowed electronics to become smarter, more connected and far more useful.

With the Internet of Things (IoT), they're allowing more than just computers to become connected to the Internet. This aims to make the life of the average person easier, better and more care-free.

Let's examine why the Internet of Things has become such a powerful idea that an estimated one out of every five developers currently works on an IoT project.


What is the Internet of Things?

The Internet of Things hinges on one seemingly simple concept: electronics can be embedded in machines, clothing, animals and even people to provide a networked world where the whole is more than just the sum of its parts.

For example, consider how the Internet of Things can influence things like refrigerators. They can be networked directly to the manufacturer for readings that can warn if the refrigerator is about to malfunction. They can even be connected to a grocery shopping service to allow someone to restock them automatically or to notify the owner that the refrigerator is almost out of an item.

The most interesting notion about the Internet of Things is that it's not just a situation where one “thing” connects with a party. They typically communicate with other things, which in turn allows for a network of automated processes to occur.

These processes can simplify and expedite tedious tasks to make everyday life for everyone easier, which is why projects involving the Internet of Things are so popular.


How Prevalent is IoT Development?

An estimated one in five developers are currently developing projects for the Internet of Things. Their chosen languages vary widely because of the flexibility that IoT enjoys.

For example, IoT projects that hinge on interacting with mobile phones tend to have apps written in JavaScript or Java. The back-end code that runs the IoT functionality for machines tends to be written in Assembly, C++,Java,Perl,Pythonor another compiled language for efficiency.

To put the growth of IoT work into perspective, Evans Data Corp. performed research to create predictions about IoT projects in 2014. They stated that 17% of companies would be developing IoT projects.

In this year, that figure's risen to a solid 19%. Given the fact that 44% of developers have stated that they will enter into the IoT scene this year or next, this means that development will only grow in the coming future.


The Future Involving the Internet of Things

Development of IoT-related projects will likely explode in the next few years. The advantages it brings, such as more efficient work in manufacturing environments and the projected 15% savings to the restaurant industry over the next five years, will make it one of the most valuable technological changes in the near future.

Without a comprehensive understanding of the Internet of Things and the skills to lead IoT projects, businesses and developers may find themselves falling behind. Don't let the Internet of Things pass you by.

There has been and continues to be a plethora of observational studies by different researchers in the publishing industry focused on how e-books have affected hard-copy book sales. Evidence from these studies has indicated that there is a significant and monumental shift away from hard-copy books to e-books.[1]These findings precipitate fears that hard-copy books might become more expensive in the near future as they begin to be less available.  This scenario could escalate to the point where only collectors of hard-copy books are willing to pay the high price for ownership.

The founder of Amazon, Jeff Bezos, made a statement in July 2010 that sales of digital books had significantly outstripped U.S. sales of hard-copy. He claimed that Amazon had sold 143 digital books for its e-reader, the Kindle, for every 100 hard-back books over the past three months. The pace of this change was unprecedented;  Amazon said that in the four weeks of June 2010, the rate of sales had reached 180 e-books for every 100 hard-backs sold. Bezos said sales of the Kindle and e-books had reached a "tipping point", with five authors including Steig Larsson, the writer of Girl with a Dragon Tattoo, and Stephenie Meyer, who penned the Twilight series, each selling more than 500,000 digital books.[2] Earlier in July 2010, Hachette said that James Patterson had sold 1.1m e-books to date.

According to a report made by Publishers Weekly, for the first quarter of 2011, e-book sales were up 159.8%; netting sales of $233.1 million. Although adult hard-cover and mass market paperback hard-copies had continued to sell, posting gains in March, all the print segments had declined for the first quarter with the nine mass market houses that report sales. Their findings revealed a 23.4% sales decline, and that children’s paper-back publishers had also declined by 24.1%.[3] E-book sales easily out-distanced mass market paperback sales in the first quarter of 2011 with mass market sales of hard-copy books falling to $123.3 million compared to e-books’ $233.1 million in sales.

According to .net sales report by the March Association of American Publishers (AAP) which collected data and statistics from 1,189 publishers, the adult e-Book sales were $282.3 million in comparison to adult hard-cover book sales which counted $229.6 million during the first quarter of 2012. During the same period in 2011, eBooks revenues were $220.4 million.[4] These reports indicate a disconcerting diminishing demand for hard-copy books.