How to find row in database by column value?

Question

MySQL

I am writing a small rest service using Spring Boot. I have an entity and an interface that inherits from CrudRepository. I need to get my entity with the necessary data, which must be found by the value of the column. I have only seen repository.findById(). Question: is it possible to find a line in the database by value, not by Id. I am using MySQL. In theory, you can write a sql query, so there must be such a function. So right?

Answer 1

Of course you can. Do you read the documentation?

Answer 2

select user_id, username, email
  from my_table
  where email='[email protected]'