linux_wiki:create_a_simple_database_schema

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Create A Simple Database Schema

General Information

Creating a simple database in MariaDB.


Lab Setup

The following virtual machines will be used:

  • server2.example.com (192.168.1.151) → Database here

Previous Section Completed


Basic Database Commands

Connect to the database

mysql -u root -p


Show databases available

MariaDB [(none)]> SHOW DATABASES;


Open a database

MariaDB [(none)]> USE mysql;


Display tables in the database

MariaDB [(mysql)]> SHOW TABLES;


Display all (SELECT *) contents of the table 'host'

MariaDB [(mysql)]> SELECT * FROM host;


Show details of the table 'host'

MariaDB [(mysql)]> DESCRIBE host;

Create a Database


Create a database called 'emails'

MariaDB [(none)]> CREATE DATABASE emails;


Open the new database

MariaDB [(none)]> USE emails;


Create a new table in the emails database

MariaDB [emails]> CREATE TABLE users (userID INT AUTO_INCREMENT, userFirstName CHAR(50), userLastName CHAR(50), userEmailAddress CHAR(50), PRIMARY KEY (userid)) AUTO_INCREMENT = 100;
  • When you create a table, you must define the names of the columns and the type of data they should contain
  • Column Definitions
    • userID INT → Named userID and of type integer
      • AUTO_INCREMENT → Auto increment the entries in this column
    • userFirstName char(25) → Named userFirstName and of type characters up to 25 long
    • PRIMARY KEY (userid) → The userid column is the primary sorting key
  • Table Options
    • AUTO_INCREMENT = 100 → Start userid at 100


Show the tables in the emails DB, display contents of the users table, show the data types in the users table.

MariaDB [emails]> SHOW TABLES;
MariaDB [emails]> SELECT * FROM users;
MariaDB [emails]> DESCRIBE users;

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  • Last modified: 2019/05/25 23:50
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