How To Become An SQL Specialist?

 

SQL skills are extremely valuable in this increasingly digitised economy,with demand for SQL developers also on a continuous rise. However, just knowing the basics of SQL will not help you secure top industry jobs. In order to excel in the field, you need to diversify your skillset and master certain intermediate concepts.   Once you have learnt about SQL dialects, importing SQL data, and writing basic SQL queries, upgrade your skillset to more advanced concepts. And if you want a guide on where to start, read ahead for a list of intermediate SQL concepts that you must master in order to become an SQL specialist.

 

Advanced SQL Concepts

SQL Sublanguages

SQL contains five main sublanguages which refer to different tasks. These are listed below. In order to master SQL, you need to learn all these languages. 

• DDL (Data Definition Language).
• DML (Data Manipulation Language).
• DCL (Data Control Language).
• TCL (Transaction Control Language).
• DQL (Data Query Language).

 

Unions and Joins

Another concept that you must master in order to become an SQL specialist is Unions and Joins. The data used by SQL developers are spread across multiple tables, and SQL can be used to merge these tables and combine all the data in one place. UNION and JOIN deal with tables. A UNION can stack two tables with identical columns on top of each other. And different Joins will help return combinations of rows from the tables being joined together. 

 

 

SQL Syntax

Once you have learnt the basics of SQL syntax such as the functions SELECT, FROM, WHERE, GROUP BY and become proficient in database design, you are well on your way to learning advanced SQL syntax. What does that entail, you ask? Read on for a list of advanced SQL syntax you need to master in order to become an SQL specialist.

• SQL is used to aggregate data by sum, average, maximum, minimum, etc. This function is useful to present your data in meaningful ways and data analysis. It works in practice because you can use the SELECT statement to return a simple aggregation for data presentation. You can also use a GROUP BY statement to create an excel pivot table out of data. You can also use grouped data paired to a categorical variable and filter the aggregations using a HAVING statement. This will narrow your query even further.
• Like the Excel IF function, an SQL case statement states that if data in a column matches a specific criterion, return "this". While mastering SQL, you will learn how to reclassify quantitative data as categorical by arranging values into "high", "medium", or "low".
• Subqueries create a temporary table from your data that can be used as a new table to query from. Subqueries have various uses and are generally found in either the FROM or the WHERE statement. 
• Dates and times are a complicated part of data languages. Dates can act like pieces of information and in some cases they are treated as actual dates. SQL syntax can then be used to break data down into units of months or years. As there are many different ways to do this, dates are times are considered more advanced SQL syntax functions.

 

Grow Your SQL Thinking

When you want to become an SQL specialist, you need to think of business questions more critically. The theory is all well and good, but it is hard to translate questions into SQL queries in practice.

 

Outline Your Query

First things first, before beginning to type, create an outline or overview of the different pieces you need for your query. For instance, do you need to filter data using a where statement? Do you need to use aggregate functions? 

 

Create a Roadmap

It is always important at an advanced stage of SQL for a specialist to develop multiple ways of doing the same thing. This will help will quality checks and validation of results. 

 

Brainstorm Your Query

Use code commenting on writing your business question. This will help guide your SQL query.

 

Data Dictionary

An SQL specialist must know how to compile a central depository for data elements they are using. This data dictionary must contain descriptions of different tables and fields used and include different data types in each column (character, integer, money, date, etc.) and a brief column description. 

 

Test Your Query

Testing your query is extremely important. Build your query at a time and run it frequently to ensure it works properly. By adding pieces one at a time, you avoid going through the code line by line and save time.

 

Profile Your Table

Before performing queries, you need to first understand the data elements. Begin with viewing the entire database, then narrowing down to a few columns and then analysing values - both categorical and quantitative - all to have an overview of the information contained in the table.

 

Assumptions

Keep a list of assumptions at hand when writing data code so that you can track your limitations and dependencies. 

 

Quality Checks

Once you have finished writing your query, you still need to understand the results. Subsequently, you must perform quality checks to confirm analysis understand your results and perform quality checks to make sure your analysis is correct. 

 

Practice 

Last but not least, in order to become a pro at SQL coding, it is important to practice any chance you get. Test code, check if it works, modify, run again, and so on till you become proficient in coding principles and syntax. 

 

Professional Certifications to Boost your CV 

In this article, we discussed the advanced SQL skills and concepts you need to master to become an SQL specialist. However, it is impossible to acquire all these skills sitting right at home. Help boost your CV and also receive guided assistance by the option for professional SQL certifications.

A database developer is in high demand and can be employed in various roles and working on different responsibilities such as data analysis, web analysis, business intelligence, data modeling, database administration, and database design. But such jobs require experts with high-level skills or experience. 

What is the solution? An SQL course. SQL Course Fees in India depend on the particular course and range from INR 6,000 - INR 20,000. And are a small cost for the long-term investment and high-paying jobs you stand to gain after completing the course. An SQL course is the perfect bridge between basic knowledge and advanced skills and is bound to get you the job of your dreams. 

 

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