Lecture Notes: Creating, Altering, and Dropping a Database

Introduction to Databases

• Database Definition: A database acts like a folder, a container for data.
• Tables: Considered as files within the folder.

Creating a Database

• SQL Statement: CREATE DATABASE followed by a unique database name.
  • Example: CREATE DATABASE myDB;
• Case Sensitivity: MySQL keywords are not case-sensitive. Preferences can vary:
  • All uppercase: CREATE
  • Capitalize first letter: Create
  • All lowercase: create
• Execution: Click the lightning bolt button to execute the statement.
• Verification: Check the schemas tab and refresh to see the new database.

Using a Database

• Set as Default:
  • Right-click on the database and select 'Set as Default Schema'.
  • Or use the command: USE myDB;

Dropping a Database

• SQL Statement: DROP DATABASE followed by the database name.
  • Example: DROP DATABASE myDB;
• Implication: Permanently deletes the database.
• Recreation: Can recreate the database if needed: CREATE DATABASE myDB;

Altering a Database

• Features for Beginners:
  • Setting a database to read-only.
  • Enabling encryption (not covered in detail).
• Read-Only Mode:
  • Command: ALTER DATABASE myDB READ ONLY = 1;
  • Prevents any modifications but allows data access.
• Attempting to Drop a Read-Only Database:
  • Results in error: Schema myDB is in read only mode.
  • To disable: ALTER DATABASE myDB READ ONLY = 0;

Conclusion

• Summary: Steps to create, use, drop, and alter a database.
• Next Topic: Creation of tables within the database.