Essential Database Cheatsheet

20 terms

This glossary is dedicated to database students who want to learn the basics of database management. Databases are a very technical and important skill to know as a Computer Science student. It will save students from the ton of new technical terms that can be overwhelming and scary at first. I have carefully selected important terms that students cannot afford to ignore.

aliases: A temporary name is assigned to a table or a column within a table for the duration of a specific query. An allias is created using the "AS" keyword.
atomicity: One property of relational database transactions is their ability to ensure that a set of database operations either all occurs or none occurs. This is known as isolation, which guarantees that queries cannot be divided into smaller parts like an atom.
commit: A command used to permanently save any changes made during a transaction. Once the commit command is executed, the database cannot revert back to its previous state.
Create, Read, Update, Delete (CRUD): Essentials basic operations that can be performed with most traditional database systems. These commands are the backbone for interacting with any database.
data types: The type of data stored in a database column is crucial in determining how SQL will interact with the stored information. These types are typically divided into three main categories: String, Numeric, and Dates.
DataBase Management System (DBMS): Nothing more than a computerized data-keeping system used by database manager.
databases: A database is an organized collection of data or a type of data store based on the use of a database management system (DBMS).
foreign key: A constraint is a crucial element used to establish a connection between two tables. A FOREIGN KEY is a field or a group of fields in one table that points to the PRIMARY KEY in another table.
Not only SQL (NoSQL): It is an approach to database design that enables the storage and querying of data outside the traditional structures found in relational databases.
operator: It is used for performing mathematical calculations, comparing values, and combining data from different tables.
primary key: A constraint that serves to uniquely identify each record in a table. It must contain UNIQUE values, and cannot contain NULL values. It is important to note that a table can only have one primary key. Additionally, the primary key can be composed of either a single column or multiple columns (fields) within the table.
query: It is a request to databases to fetch, add, modify or delete the information.
relational database: It organizes data in tables, with rows and columns representing different data attributes and the various relationships between data values.
relationship: A relationship refers to the way in which different entities (or tables) are connected to each other. It can be one-to-one; one-to-many or many-to-many.
rollback: A command used to undo any unsaved transactions in the database. It can only be used to revert changes made since the last COMMIT.
schema: It visually and logicaly describes the organization and storage of data in a database and defines the relationship between various tables.
Structured Query Language (SQL): It is a programming language used to store and process information in a relational database.
table: Tables are database objects that contain all the data in a database. In tables, data is logically organized in a row-and-column format similar to a spreadsheet.
transaction: It is a unit or sequence of work that is performed on a database.
trigger: It allows you to specify SQL actions that should be executed automatically when a specific event occurs in the database.