Sunday, February 27, 2022

How to store and Query Hierarchical Data in Database using SQL? Example Tutorial

What methods do you use to detect hierarchical data and query it? We're about to get answers to two popular SQL queries.

When working with SQL and relational databases, querying hierarchical data is a typical occurrence. It's not that hierarchical data is mysterious or uncommon; on the contrary, it's all around us. So, why is hierarchical data so difficult to work within relational databases? The issues arise mostly when converting hierarchical data to relational database concepts.

What is Primary key in SQL? How to choose Primary key in table? Example

If you've ever dealt with databases, you've almost certainly come across the term - primary key (PK). And if you're following this series to learn about databases, this piece should help you understand what the PK is all about. Even if you're a database specialist, you could learn something new or improve your skills. So sit back, relax, and let's get started with the PKs.

Sunday, February 20, 2022

How to use WHERE , LIKE, and BETWEEN in SQL for Filtering Rows? Example Tutorial

You may be thinking why is the filtering of data needed? Because you utilize the WHERE clause when changing data with DELETE and UPDATE statements, if you've been following these Database Fundamentals posts, you've already seen it. It's also been used to restrict the values returned from a SELECT operation multiple times in this series.

Tuesday, February 8, 2022

How to use LEFT, RIGHT, INNER, OUTER, FULL, and SELF JOIN in SQL? Example Tutorial

What are joins and why are they required?

Hello, everyone. Have you ever faced any issues while generating reports or loading data but were using data of just one table was not enough? One table's data is typically insufficient to provide important insights when doing sophisticated analytical processing and data discovery, therefore merging numerous tables is required. SQL, as a method for communicating with relational databases, allows you to create relationships between tables