SQL (Structured Query Language) is a domain-specific programming language that is used to handle data in database management systems. SQL programming skills are highly sought after in the market because Database Management Systems (DBMS) are employed in almost every software application. To be considered for a position, candidates must pass an interview in which they will be asked a number of SQL interview questions. The questions and answers that will most likely be asked during the SQL interview are listed below. Candidates with a few years of experience are asked SQL basic to advanced level SQL interview questions, depending on their skill and other factors. The list below contains all of the SQL technical interview questions for freshers, as well as SQL server interview questions for experienced candidates and some SQL query interview questions. Let’s dive in.
What is a database management system (DBMS) and how does it work?
A database management system (DBMS) is a piece of software that oversees database creation, maintenance, and use. A database management system (DBMS) is a sort of file manager that works with data in a database instead of saving it to a file system.
What exactly is an RDBMS (relational database management system)?
The abbreviation for Relational Database Management System (RDBMS) is Relational Database Management System. RDBMS stores data in a sequence of tables connected by common fields between table columns. It also has relational operators for manipulating the data in the tables.
What are tables and Fields?
In a model, a table is a collection of data structured by columns and rows. Horizontal rows are horizontal, but vertical columns are vertical. A table contains a fixed number of columns, known as fields, but any number of rows, or records, can be added.
What is a SQL
SQL (Structured Query Language) is a computer language for interacting with databases. This is a computer language used to retrieve, update, insert, and delete data from a database.
A standard SQL command is selected.
What is Database?
A database is basically an organized representation of data that makes data access, storage, retrieval, and management a breeze. This is a type of structured data that may be accessed in a number of ways.
What is a primary key?
A primary key is a group of fields in a database that uniquely identifies a record. This is a special kind of unique key that has a NOT NULL requirement. It means that the primary key’s values cannot be NULL.
What is a unique key?
A unique key constraint was used to identify each record in the database. This assures that the column (or set of columns) is one-of-a-kind. On a main key constraint, an automated unique constraint is defined. However, this is not the case in the case of Unique Key. Multiple unique constraints can be defined per table, but only one main key constraint.
What are all the different normalizations?
The common types are divided into five categories, as shown below -.
1NF (First Normal Form): This should remove all duplicate columns from the table. Unique columns are detected and tables with similar data are established.
2NF (Second Normal Form): All of the first normal form’s requirements are met. Creating associations between subsets of data by putting them in various tables and using primary keys.
3NF (Third Normal Form): This should meet all of the 2NF requirements. Getting rid of columns that aren’t constrained by main keys.
It should satisfy all of the requirements of the third normal form and have no multi-valued dependents. 4NF (Fourth Normal Form): It should meet all of the requirements of the third normal form and have no multi-valued dependencies.
Final Thoughts: It’s impossible to cover all of the questions asked in a SQL interview in a single blog post. However, the questions listed above are the most frequently asked in SQL interviews. If you want to learn more about SQL, you can always learn for free on youtube. There are thousands of SQL tutorials on YouTube. Use Career Ninja‘s LearnTube for hand-holding training on YouTube. LearnTube organizes the results of your YouTube search into a course framework. If you want to learn “SQL tutorials”, search the term on LearnTube and it will show you a bunch of youtube videos like an online course. As a beginner, you’ll click through the videos from the first to the last, as if you were taking an online course tailored specifically for you.
