7 Essential SQL Programming Tips for Beginners
Nowadays, almost all businesses from small ecommerce startups to Fortune 500 corporations appreciate the value of Big Data (large data sets—both structured and unstructured) to run their operations. But, a large volume of raw data on its own isn't very useful. Businesses need to manage this data using databases, which is where SQL database systems come into play.
SQL (often pronounced like the word “sequel”) stands for Structured Query Language. It is a programming language that allows communication with databases to manage all the data they contain.
With all the buzz in the tech world about Big Data today, demand for database administration experts has exploded; and as a result, demand for SQL developers and programmers has also skyrocketed.
Working as a SQL programmer can be a lucrative career option, with a median pay of $90,070 per year or $43.31 per hour as of 2018, according to the U.S. Bureau of Labor Statistics (BLS).
However, coding errors are quite common with SQL programmers when starting out. This is why it is important to understands the coding process properly, especially for beginners.
Essentials to Understand and Execute SQL Coding Process
Programmers have to be conscious with the coding syntax, and the right syntax has to be used in the right places. This is critical because it can be quite challenging to find and fix coding errors or mistakes.
For beginners, mistakes are not rare or uncommon. Every beginner makes coding mistakes sometimes, and this is absolutely true for SQL programmers. But, as a SQL programmer, you need to deal with all coding language errors swiftly and avoid basic and common errors.
That means following the right format for coding so that basic mistakes can be avoided as much as possible. To assist you in this regard, here are some crucial tips on SQL programming for beginners:
1. Placement of Opening and Closing Parentheses
Many beginners make one common mistake, and that is they open the parentheses but forget to close it. As a result, a coding error happens.
Such mistakes become difficult to trace if you habitually do this for quite a few times. The best way to avoid the error is to remember to close the parentheses. However, if that does not work for you, a different method or strategy can be tried.
The alternative method is to write the opening and closing parentheses right at the beginning. Now, you can write the rest of the coding within the parentheses. This is an orthodox method, but it works quite seamlessly.
If parentheses are not balanced, they shall lead to syntax errors.
2. Use Comma as Separator
In SQL coding, users need to understand the function of every character. Among various characters, the comma has come to be regarded as very important, and it is used quite frequently. If you do not use comma frequently, you may come across syntax errors.
Now, the comma has to be used properly where it is applicable. A comma acts as a separator in most cases for all sorts of programming languages. For SQL, it is not different.
When you are creating a table in SQL, remember to place an extra comma after the final comma name. Many people do not practice that, and as a result, SQL error happens. So, understand proper comma use and avoid this particular error, which is often done by beginners in SQL coding.
3. Use of the owner/Schema Name
The object name has to be paired with the schema name or owner name. Many beginners forget to do that, and that results in programming issues. This is a common reason why database bugs are found. So, why is it so important to use the owner or schema name?
Basically, when a specific schema name has not been provided, the SQL server engine tries to verify all the schema names. As a result, the server takes a lot of time to find suitable result against the queries. End users shall find it extremely daunting, as the server will fetch slow replies against the queries as it will review all the schema names that are available on the SQL server.
4. Using the Operator Name
The right use of the operator name is absolutely important for the purpose of error-free coding for SQL server. Errors can happen at any time, and when you find errors, you need to resolve them with precision.
In the "select" statements of SQL, you should not use the * operator. Instead of the operator name, you must use the column name. Now, the question is, why is it so important? Well, it is important as SQL server starts scanning from the column names. It automatically replaces all the * operator with the column name in the SQL "select" statement.
Offering the column names to the SQL search server will help to find results against the queries sooner. It will cut down the time meticulously, and thus eventually long database would be easier to be managed. When you do not use column name instead of an * operator, you come across a lot of troubles. The database takes a long time to give answers to the search queries.
5. Understanding the Nullable Columns
When you are comparing the nullable columns, you should not use "not in." Instead of that, you should use "not exists." This is the standard procedure to deal with the nullable columns. All experienced and skilled SQL programmers follow this norm.
When you use the "not in" command, the SQL server will check each result in order to understand whether it is null or not. When you use the "not exists," the server will not compare the columns with nulls. As a result, the server will work faster to fetch query results.
Managing large data will become easier with this method.
6. Dealing with Table Variable and Joints
If you want to become a more successful and skilled SQL developer or programmer, you need to have a clear conception of tables and joints.
Do not use the table variable in the joins. It is to be noted that every table variable works in a faster way. They are efficient in a lot of situations, as well.
The performance becomes horrible when you use the joins with the table variables. It messed up the server. As a result, the SQL server takes a lot of time to return answers against the queries.
7. Procedure Name Storage
Last but not least, understand the key of procedure name storage with "sp_." SQL server always checks in the system when the stored procedure has been named as "sp_."
Providing a name without "sp_" will help to reduce the time for unnecessary checking. So, the database server will act swiftly in that case.
When the database server does not act swiftly, it causes technical issues. Managing a large database will become extremely difficult when the database server is not managed or maintained properly. Keep this aspect in mind and manage the database in this manner to ensure it works perfectly.