SQL also known as; Structured Query Language is a type of programming language that is mainly used in systems based in database management. Knowing how to build ana manage an SQL database is a highly sought-after skill on the job market at the moment. Any company that collects any form of data is likely to need a group of skilled professionals fluent in SQL programming techniques so it’s important to make sure you known the ins and outs of how it works. You don’t want to get caught with no answer after getting asked some SQL interview questions for your dream programming job so here are the basics to making sure you know how SQL works.
What is the basic knowledge?
It’s always important to make sure when you start a new project to give yourself a refresh on the basic aspects of what you’re doing, weather you’re a professional or a completely new beginner. Building an SQL database can be quite a complex and sometimes laborious so make sure that you know about DBMS and RDBMS, what primary and unique keys are, what a join. Familiarize yourself with the vocabulary and definitions that run the SQL and then you can get started.
What should I include in the database?
Once you have this work done, its important to make sure that you decide what needs to be included in the table, so you know how to set them up. For example, you are working for a shipping department for an online store. The information you have on customers includes, Name, address, phone number, age, email address and delivery date. You can decide that for the delivery drivers, the only information that they would need is the Name, address, delivery date and maybe the phone number. By doing this you are able to make sure that only the relevant information goes to the right people and it makes building your database a much less cluttered experience.
What should I designate as the primary key?
The primary key is the field in the table that is completely unique. At often times this should be something like an order number, a product ID, a username. Some form of unique piece of data that separates the different entries. This is mainly used as a way to quicky identify separate entries of data within the table and help later on when searching through the tables for specific information.
How do I organize my tables?
Once you have your tables designated with the right information it is very useful to create a table diagram. This puts all of your tables in small windows next to each other allowing you to see all the information going through your tables at once. Not only is this useful as a way to mark your progress but doing so allows you to create certain relationships between the different tables. This will ensure that two separate tables that have matching sections, are linked and cross referenced with each other.
Why are queries important?
Queries are effectively the fruit of your labor. A query is basically a way of saying a search. Just as you would google something on the internet, in a database you would use a query. Being able to quickly and effectively query is very important as it shows that your tables are working as they are intended to or more importantly aren’t. If you use a query and find that you don’t get the right information, it shows that you need to go back into the database to do some troubleshooting which is better than getting complaints about it not working properly down the line.
And there you have it, 5 basic tips that will make sure your SQL is up to scratch and ready to be used in the future.