5 posts tagged with "database"

"I changed the object's failedLoginAttempts field, but when I query the database again, it's back to the old value! In high school, changing object properties just worked - why do I need to call save() in Spring Boot?" This is the fundamental difference between in-memory objects (what you learned in school) and database-backed objects (what you use in production). Let's understand why object changes don't automatically persist to the database.

Your Spring Boot app starts, H2 Console connects, but... where are the tables? Here's how to test if your H2 database is working and fix the most common issue: missing tables.

What if I told you that adding a single annotation to a Java class automatically creates a database table with all the right columns, types, and constraints? Meet @Entity - the annotation that bridges Java objects and database tables.

Your Spring Boot app won't start and you see a "database is locked" error. The culprit? Multiple instances of your application running simultaneously, all trying to access the same database file. Here's how to identify and fix this common problem.

Ever wondered what those spring.datasource.* and spring.jpa.* properties actually do when your Spring Boot app starts? Let's trace the complete journey from configuration file to running database, step by step.