Practicing SQL with Oracle Live SQL

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Being a data analyst needs to know how to retrieve data from a database. I have attempted various courses in learning SQL queries, which generally contain table names, variables, relationships, and questions that need to be solved related to the data. For example, HackerRank provides a number of interesting challenges starting from easy, medium, to advanced levels.

However, practicing SQL skills by yourself is challenging. This is because if we have never handled a company database at all, we need to create our own database on a local server. This can be done by installing a database application (e.g. MySQL) and create our own queries to build tables and insert values. This is definitely not practical if we want to practice SQL skills instantly (using an existing database).

Oracle Live SQL Home Page

A Solution

Oracle Live SQL provides a website that can be accessed online containing various databases that we can explore ourselves. Interestingly, we can also create our own database if we want to! Without the needs to install any application, we can easily practice our SQL skills, right? All you have to do is create an account and you can immediately access the various features.

Oracle Live SQL Menu Screen

Oracle Live SQL is divided into 8 menus:

1. Home
2. SQL Worksheet, where we can build and run queries.
3. My Session, contains the history of queries.
4. Schema, contains an existing (or custom-made) database.
5. Quick SQL
6. My Scripts, contains scripts that have been saved.
7. My Tutorial, contains the tutorial steps that have been prepared.
8. Code Library, contains queries for further study ( created by the developer).

Available Database

Accessible Database

In this Schema, we can see that there are 9 databases that we can explore. Each database has a different topic. Let’s try to check the database for Order Entry (OE).

Database Order Entry (OE)

Here we can see that there are 6 tables, 1 type, and 1 function. We focus on discussing tables first since to explore the database, we need to understand each table first.

Let’s say we want to look at the CUSTOMERS table.

Table Attributes for CUSTOMERS

When we click CUSTOMERS, we can see the details of the table starting from attributes, columns, indexes, triggers, and constraints. To see what data is available in this table, we can click columns.

Columns in Customers Table (10 out of 15 columns)

Here we can see that the CUSTOMERS table contains information about each customer based on CUSTOMER_ID. To view the complete table, we can click Actions then Query:

Actions -> Query

After clicking Query, we are instantly redirected to the SQL Worksheet and a query is automatically provided to view all the data in the CUSTOMERS table:

Query yang dihasilkan otomatis

By clicking Run, we can see the data available in the table:

In this way, we can see all the data in the CUSTOMERS table. Afterward, we can use it to solve a problem (case study).

That’s the end of this article. In the future, I will create a case study-based project using the Oracle Live SQL platform.

Thank you! :)