SQL
What does the following query do? SELECT * FROM customers;
Selects everything from the customers table.
What is a primary key?
a primary key uniquely identifies a row in a table.
What does CRUD stand for?
Create, Read, Update, Delete
What is an array list?
a resizable array with which elements can be added to or removed whenever you want
What does ORDER BY do?
Specifies how data is sorted in a results set.
What does JSON stand for?
JavaScript object notation
what is the name of the in memory database commonly used with java spring
H2
What does the 'extends' keyword do?
You use this keyword to inherit all public attributes and methods from a parent class
name 3 SQL statements
SELECT, UPDATE, DELETE, INSERT, etc.
What are the two most popular types of databases?
Relational and NoSQL databases
What is the difference between PUT and PATCH
Put replaces an entire set of data while patch replaces only a certain part
What is a constructor?
a method that is called automatically when you create an instance of a a class object
true or false: in SQL, keywords MUST be capitalized for the query to work properly?
false, capitalizing SQL keywords is common practice but not required
if your database is set to 'cascade on delete' what does that mean?
What is the purpose of @Override?
@Override annotation informs the compiler that the element is meant to take over an element declared in a superclass.
What is over-loading in java?
when you have 2 methods with the same name, in the same class, but different parameters
What is an aggregate function in SQL?
An aggregate function performs a calculation on a set of values, and returns a single value.
Define an intermediary table in a database
A table containing the references to two separate tables defined by their primary key
What is a Response Entity in spring?
ResponseEntity is meant to represent the entire HTTP response. You can control anything that goes into it: status code, headers, and body.
Under what circumstances do you use the this keyword?
Can implicitly or explicitly be used for clarity as to which variable is being referenced with instance variables; allows an object to refer to itself