Basic Concepts of Databases: Tables, Rows, Columns, and Relationships
Structured systems for managing, storing, and retrieving data are called databases. Tables are the building blocks of all databases; they can be seen as spreadsheet-like grids. Rows and columns make up each table; rows are individual records, and columns are these records’ various attributes. For example, in a customer database, every row could represent a distinct customer, and every column could represent various customer attributes like name, email, and past purchases.
The ability of databases to create relationships between various tables is what gives them power. A comprehensive view can be obtained by integrating and retrieving data from multiple tables through these relationships. For instance, distinct tables for customers, orders, and products may be present in a sales database. Finding complex queries like the total amount spent by each customer is made possible by creating relationships between these tables.
Types of Databases: Relational vs. Non-Relational
Relational and non-relational databases are the two primary categories. Relational models are the structure used by relational databases, including MySQL, PostgreSQL, and Oracle. Tables hold the data in this model, and keys specify the relationships between the tables. This structure is very well-organized and appropriate for situations where data integrity must be maintained.
A different strategy is used by non-relational databases, or NoSQL databases, such as Couchbase, Cassandra, and MongoDB. Their design aims to increase flexibility and scalability, frequently utilizing formats like document-based models, wide-column stores, and key-value pairs. Because of their adaptability, NoSQL databases are ideal for managing massive amounts of semi-structured or unstructured data, like social media posts, as well as for applications that need to scale horizontally.