The Best Exercises and Quizzes to Help You Learn SQL

SQL is an acronym for Structured Query Language. SQL is a computer language that allows users to navigate, store, manage, and retrieve data from relational databases. If you’re interested in a career as an SQL database administrator or business intelligence analyst, you need SQL skills. An ideal way to acquire these skills and practice for interviews is through SQL exercises.

So, how or where can you get help with SQL? Which practice platforms have the best SQL exercises? All these questions and more will be answered in this article. You’ll discover the best SQL practice exercises to help you learn SQL faster, even as a beginner with no technical skills. Ready to start building your expert SQL skills? Keep reading.

SQL Exercises to Help You Learn SQL

The SQL exercises listed below contain basic and advanced exercises to help you understand the practical applications of this query language. Each interactive exercise category covers a major concept of the SQL language and how you can get started with mastering it.

10 Sql Exercises and Practice Problems (With Solutions)

1. How do you insert data in SQL tables?

SQL tables are database objects that are logically organized in related rows and columns. Every SQL database is organized in tables. These tables are stored based on their various names. The rows contain information like the column records, and the columns contain details like the name and type of data. So, how do you insert data in SQL tables?

Solution: To insert data in an SQL table, you need to create an “insert into table” statement. There are four types of statements used in a data structure. To implement this function, you have to define details like the table name, column data list, and values. The syntax looks like this: INSERT INTO table_name (column_list) VALUES (column_values) ;

2. How do you create relationships between database tables?

Relationships in SQL are the defined connections between tables. The relationships between the tables are created with joint statements that make it easy to retrieve data from the tables using SQL queries. So, how do you create relationships between database tables?

Solution: Creating relationships in SQL database tables requires you to visit the database designer and click on the row selector tab for the number of columns you want to associate with columns in another table. Then, you drag the columns you selected to the specific table. At this stage, two dialog boxes will open up, these being tables and columns, and the foreign key relationship. You can edit the table values or change the mappings before choosing “OK”.

3. How are views created in SQL?

Views in SQL are abstract tables that contain rows and columns, as well as a subset of data values from different tables, just like in a physical table. A view can be created from multiple tables, depending on the SQL server query. Each view requires associative names and makes it easy to structure and retrieve data. So, how are views created in SQL?

Solution: To create a view in SQL, you need to use the CREATE VIEW statement. You can create the view from one or multiple tables. You can even create a view from another view. The syntax for creating views looks like this: CREATE VIEW view_name AS; SELECT column1, column2….. FROM table_name; WHERE [condition];

4. How do you apply database normalization in SQL?

Database normalization in SQL is a technique used to organize and structure attributes and relations in a particular database based on normal forms, to improve the quality of the data. It involves splitting complex tables into simpler and smaller formats so that the existing data values can be assessed, deleted, or updated. So, how do you apply database normalization in SQL?

Solution: To apply normalization in SQL, you have to specify a set of rules. These rules are called Normal Forms. The database normalization process in SQL contains six types: first normal form (1NF), second normal form (2NF), third normal form (3NF), Boyce-Codd normal form or fourth normal form (BCNF or 4NF), fifth normal form (5NF) and sixth normal form (6NF).

5. How are transactions performed in SQL?

Transactions in SQL are a series of sequential operations that are done through SQL queries or statements as just one unit of work to achieve a logical goal. Transactions are either applied or unapplied from a database. All transactions have these four properties: atomicity, consistency, isolation, and durability. So, how are transactions performed in an SQL database?

Solution: Transactions in SQL are performed through control commands. The control commands include the “COMMIT;” command, the “ROLLBACK;” command, the “SAVEPOINT SAVEPOINT_NAME;” command, and the “SET TRANSACTION [ READ WRITE | READ ONLY ];” command. These control commands are used in union with these DML commands: insert, update, and delete.

6. How do you clone a table in SQL?

In the course of using an SQL database, you will need to create a replica of a specific table, on one or two occasions. You can’t do that with the CREATE or SELECT command, since they won’t come with the data and indexes from the previous table. In this case, you’ll need to clone the table and all the data in it. So, how do you clone a table in SQL?

Solution: To clone a table in SQL, you need to install an SQL library or package. There are several to choose from. However, if you use the MySQL library, all you have to do is display the CREATE TABLE command to acquire a CREATE TABLE statement that defines the table structure. Then, edit the name of the statement and execute it. If you want to copy the values in the table, add the INSERT INTO or SELECT statement.

7. How do you apply SQL server sequences in practice?

A sequence is a list of numeric values that come in specific value orders. A sequence in an SQL server is a schema object that’s also user-defined and produces a series of numbers, having defined positions that may come in an ascending order or a descending order cycle. So, how do you generate a numeric value sequence having specified specifications?

Solution: To achieve this, you need a “create sequence” statement: CREATE SEQUENCE [ schema_name. ] sequence_name [ AS integer_type ] [ START WITH start_value ] [ INCREMENT BY increment_value ] [ { MINVALUE [ min_value ] } | { NO MINVALUE } ] [ { MAXVALUE [ max_value ] } | { NO MAXVALUE } ] [ CYCLE | { NO CYCLE } ] [ { CACHE [ cache_size] } | { NO CACHE } ];

8. How do you execute an SQL query against a database?

The EXEC command in SQL is used to execute a procedure or a string that has been stored in the database. So, how do you execute an SQL query against a database? To execute an SQL query means to run the query against the catalog of a database. The queries must first be analyzed so that the command knows which tables and columns are required.

Solution: In practice, it involves opening the query tool from your tools tab, then creating a novel query or reopening a previous query file. Next, you click on the connect icon and proceed to impute the connection criteria in the dialog box. The next step is optional, and it involves you limiting the row count to the check box by entering a number. Then, you click the execute icon.

9. How do you delete records from an SQL database?

Just as data structures and records are inserted or updated, they can also be eliminated from a table. This means that the data that is deleted can no longer be retrieved, as it ceases to exist. So, be careful when eliminating records from a table because if you don’t specify the right condition, you can lose all your data. So, how do you delete records from an SQL database?

Solution: The DELETE statement is very straightforward. The syntax is written as follows: DELETE FROM table_name WHERE condition; The WHERE condition means that the data manipulation language (DML) is restricted to certain rows based on defined criteria.

10. How do you retrieve data from an SQL database?

Retrieval in SQL means to analyze and acquire data organized in different formats in a database management system using SQL queries. The data obtained can be kept in a file, a view screen, or printed out for personal use. So, how do you retrieve data from an SQL database?

Solution: To retrieve data from a relational database system, we must use the SELECT statement. This statement allows us to identify and select the specific data we need from any table. The SELECT syntax is written in this format: SELECT column1, column2, … FROM table_name;. The columns represent the field names of the sample table you need data from.

How to Get Help with SQL

Learning SQL isn’t difficult, but mastering it requires regular practice. It also wasn’t designed as a programming language, so you don’t need to possess programming skills to use this language. If you’re interested in improving your database management skills to boost your career or just for fun, you should take advantage of these SQL learning methods.

SQL Exercises

SQL exercises are sample interview questions that help candidates learn beginner and advanced concepts in SQL. As an individual who wants to understand how databases are designed and managed, SQL query questions can help you build well-rounded knowledge. Websites like W3School and w3resource provide tutorials alongside exercises to help improve the learner’s experience.

SQL Projects

Projects are an essential part of every technical field. They show potential employers and other players in the industry that you’re a professional at what you do. Creating a portfolio of SQL projects makes it easy for prospective employers to measure your competence for an SQL job role. That’s why you need to find the right SQL project ideas and training platforms to help you build your skills.

SQL Quizzes

SQL quizzes are designed in the form of timed multiple-choice questions that often require a simple but correct answer to earn a point or reward. Some companies now incorporate SQL quizzes as part of their hiring process. So, if you’re preparing for an SQL-based interview, you should practice with platforms like Data Flair or ProProfs that give real-time experience.

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SQL Forums and Blogs

If you’re looking for a place to network with IT professionals, you should join SQL discussion forums and blogs. There are several advantages to joining these platforms. You can find learning resources and job opportunities on these platforms. You can learn to improve your SQL skills through some of the projects, tutorials, and articles shared on platforms like SQL Team and Stack Overflow.

Where Can I Practice SQL?

If you’re looking for a more structured way of practicing SQL or you’re searching for where to train for your next SQL-related job interview, the websites listed below are your best options. Find relevant lessons, challenges, and interview questions to help you build your SQL skills.

Websites to Practice SQL

• Code Grepper. Code Grepper is an ideal platform to learn SQL. It comes with multiple SQL server exercises and solutions to help beginners and advanced data professionals build their knowledge of this discipline. You’ll also find this platform useful for practicing exercise projects for other coding languages like Swift, C++, VBA, and Shell.
• TestDome. Thousands of individuals and companies use this IT skill assessment to determine proficiency with relational databases and SQL queries. If you’re interested in measuring your likely SQL job success rate, then practicing with this platform is your best option. If you score within the top 25 percent on this test, you could receive an achievement certificate.
• HackerRank. HackerRank provides a list of SQL skill tracks, tutorials, and challenges for interested candidates to attempt. The interview preparation kit was designed for job seekers who need to practice for interviews with top SQL employers. You can even take the skills certification test to help you stand out to recruiters.
• DevSkiller. DevSkiller offers any fraction of users coding tests in SQL, so they can easily build their database design skills with the SQL language and libraries, including PostgreSQL and MySQL, through mock screening and exercises for interviews.
• SQLPad. If you’re interested in discovering in-depth SQL query questions and solutions to help you succeed in your next job interview, SQLPad offers a satisfying learning experience. You can hire an interview coach to help you build your preparedness. Several users have found the SQLPad’s SQL video course and practice tests helpful.

What’s the Best Way to Learn SQL?

The best way to learn SQL is by practicing with multiple learning resources that include SQL exercises, quizzes, projects, and challenges as part of their training format. Learning through multiple formats makes it easier for you to become comfortable with SQL. Comfort breeds competence and innovation, which are essential skills for building relevance in the tech industry.

SQL Exercises FAQ