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 importance of variables in any programming language can’t be emphasised enough. Even if you are a novice, the chances are good that you will have been using variables for quite a while now.

They are the cornerstone of any language and without them we would not be able to accomplish much of anything. However, most of you up until this point have probably only been working with standard variables, variables which can hold single values such as an integer, a single character, or a string of text.

In this tutorial we are going to take a look at a more special type of variable called an array. Arrays can seem quite daunting at first glance but once you get used to working with them you will wonder how you ever managed to program without them.

The reason arrays are special is because they can hold more than one value. Think about this: say you create a variable which contains a line of text like the code below:

I suspect that many of you are familiar with the term "hard coding a value" whereby the age of an individual or their location is written into the condition (or action) of a business rule (in this case) as shown below:

if customer.age > 21 and customer.city == 'denver'

then ...

Such coding practices are perfectly expectable provided that the conditional values, age and city, never change. They become entirely unacceptable if a need for different values could be anticipated. A classic example of where this practice occurred that caused considerable heartache in the IT industry was the Y2K issue where dates were updated using only the last 2 digits of a four digit number because the first 2 digits were hard-coded to 19 i.e. 1998, 1999. All was well provided that the date did not advance to a time beyond the 1900’s since no one could be certain of what would happen when the millennia arrived (2000). A considerably amount of work (albeit boring) and money, approximately $200 billion, went into revising systems by way of software rewrites and computer chip replacements in order to thwart any detrimental outcomes. It is obvious how a simple change or an assumption can have sweeping consequences.

You may wonder what Y2K has to do with Business Rule Management Systems (BRMS). Well, what if we considered rules themselves to be hard-coded. If we were to write 100s of rules in Java, .NET or whatever language that only worked for a given scenario or assumption, would that not constitute hard-coded logic? By hard-coded, we obviously mean compiled. For example, if a credit card company has a variety of bonus campaigns, each with their own unique list of rules that may change within a week’s time, what would be the most effective way of writing software to deal with these responsibilities?

Planning on a little spring cleaning and getting rid of all those old electronics? With the way technology changes so quickly, it seems like we no sooner have one new electronic piece and there’s a new one on the market that we absolutely have to have. The result is a ton of used electronics stored away. Now it’s time to get rid of everything, here are some tips on what to do with all that old tech stuff and how to do it safely.

Save on Landfill Waste

Few people really realize where their electronics wind up when they throw them in the trash or dumpster. They assume they’re getting taken care of and just forget about them. According to the Environmental Protection Agency, one of the fastest growing components of landfill waste is electronics. The unfortunate part of this is that these electronics are filled with lead, mercury and other toxic chemicals – chemicals that find their way into our soil and water.

This results in the contamination of our lakes, streams and soil. The best way to avoid this is by knowing where your electronics are going and to dispose of them safely. Contact the recycling center in your area and ask for the best place to dispose of your old electronics.

Think of Security

Our lives are filled with electronic technology, whether it’s in the form of computers, tablets, smart phones or video games. Most of these electronics allow network sharing with people all over the world. With identity theft such a growing concern, much of our private lives and personal information is entered in the hard drives of these items.

Before you dispose of any electronics, make sure the hard drives are wiped clean of all personal information. This requires more than just “deleting” files. If you’re not sure how to correctly get rid of the information, contact a professional to do this for you. Even if you have to pay to have it done, it’s a minimal expense compared to having your private information stolen.

Find New Homes for Your Electronics

Once you’ve cleaned out your electronics of personal information, they may still be worth something to other individuals. You may know of a child or elderly person who would really appreciate a “new” computer or a tablet. Someone who has never owned a smart phone or laptop may be thrilled to suddenly own one, even if they are obsolete to you.

If you can’t find anyone that wants them, consider selling them on places like eBay, Craigslist or one of the many other online auction sites. The old saying, “one man’s junk is another man’s gold” is especially true when it comes to electronics. Many people like building computers using their own parts.

Students in computer-related programs also utilize used electronics as a form of hands-on training. Most schools also take in donated computers, televisions and cell phones. Contact your electric company or school district to get information on where you can take your old electronics. You’ll be not only cleaning out your house but also helping the environment.

Related:

Cloud Computing: What It Means and How It Could Threaten the Traditional Outsourcing Model