PostgreSQL and MySQL are both popular open-source relational database management systems (RDBMS) used in web applications.
The main difference between PostgreSQL and MySQL is in how they handle data integrity. PostgreSQL is more strict about data integrity and includes features such as foreign key constraints, views, and triggers to ensure data accuracy. MySQL is more lenient and allows developers to skip certain steps to speed up development.
For example, PostgreSQL requires a foreign key constraint to be defined when creating a new table. This means that when a new row is added to the table, it must reference an existing row in another table. MySQL does not require this, allowing developers to skip this step and speed up development.