![]() Anything that does not end in the typical should not be allowed inside that column. To prevent this from happening, columns can be designed to only let a specific type of information to be entered. For example, a column about salary should only contain numbers, right? While that is true, the people operating the databases are humans and can therefore accidentally enter something else in it. This aspect allows for much-needed data integrity. If a Table, as mentioned above, contains people’s names, job titles, manager numbers, hiring dates, salaries, and commissions, then that table will have 6 columns plus a Primary Key column that we will discuss in later sections.Įach column can be set up to allow only a specific type of information to be entered into it. In a Table that contains information about people, the columns would be used to hold different information. This is the oldest type of database and has been used for over 40 years.Ī relational database consists of 3 high-level components:Ĭolumns are used to differentiate the information we have on a single observable entity. When people talk about a database they are usually referring to a relational database. For a database however each row is called a record and each cell is called a field. Inside a spreadsheet there are columns and rows of data. You can think of a table somewhat like a spreadhseet. For example, a company may have a table for customer information and another for sales numbers. A database is made up of tables that contain columns and rows. The most efficient way to store data is with the help of a database. When multiple datasets are concerned, things can get complicated very easily and it can become time-consuming to constantly move back and forth between heaps of data. Sometimes you will need to tackle multiple datasets together to form useful insights. What you won’t be concerned with is their favorite TV show or what books they like to read.Īll data is powerful, you just have to make sure that you’re dealing with something that concerns your end goal. If you work at an insurance firm, you’ll want to have information that includes customer credit history, age, bank records, etc. What’s more necessary is that it should be relevant to your department. Organized data can be any representation of data that allows you to gather insights. The following is the script that drops all tables in case you want to refresh the sample database.Think of organized data as a good old file cabinet (but on your computer) The following script inserts data into the tables in the SQLite: Create HR Sample Database in SQLite Removing tables The following script creates the HR sample database structure in SQLite. The following script inserts data into the tables in the Oracle database: Load HR Data in Oracle Database SQLite The following script creates the HR sample database structure in Oracle Database 12c. The following script allows you to insert data into the tables: Load HR Data in SQL Server Oracle Database (>12c) The following script creates the HR sample database structure in Microsoft SQL Server. The following script allows you to insert data into the tables in PostgreSQL: Load HR Data in PostgreSQL Microsoft SQL Server The following script creates the HR sample database structure in PostgreSQL. The following script allows you to insert data into the tables in MySQL: Load HR Data in MySQL PostgreSQL The following SQL script creates the HR sample database in MySQL: Create HR Sample Database in MySQL In case you don’t have a database system to practice, you can quickly use our SQL online tool to execute the SQL statements in your web browser. If you have worked with an RDBMS such as MySQL, PostgreSQL, Oracle Database, and SQL Server, you can use the following script to create the sample database in one of these databases. Typically, you need to install a Relational Database Management System (RDBMS) to work with SQL. ![]() The following picture shows the table names and their records. The regions table stores the data of regions such as Asia, Europe, America, and the Middle East and Africa.The countries table stores the data of countries where the company is doing business.The locations table stores the location of the departments of the company.The dependents table stores the employee’s dependents.The departments table stores department data.The jobs table stores the job data including job title and salary range. ![]() The employees table stores the data of employees.The following database diagram illustrates the HR sample database: ![]() Summary: in this tutorial, you will learn about a SQL Sample Database called HR that manages the HR data of the small businesses.
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