CSUMB Learning Journal 2025

     This week marks the halfway point for our class. There is so much I've learned in this class so far and I'm excited to keep moving forward.  Briefly summarize 5 things what you have learned in the course so far.   SQL - I've learned that SQL (Structured Query Language) is used to manage and interact with relational databases. It lets you define data structures(tables), insert data, and query information using commands like SELECT, INSERT, UPDATE, and DELETE. Java Tuples - In Java, I learned that tuples are fixed-size collections of elements, used to group related values without creating a class. Java Predicates - A Java Predicate is a functional interface that represents a condition or boolean-valued function. I learned that it's commonly used in filtering operations with streams or collections, and takes one argument to return true or false. Bitmaps - I learned that a bitmap is a data structure that represents a set of bits (0s and 1s), often used to ...

  1.What is an SQL view.  How is it similar to a table? In what ways is it different (think about primary keys,  insert, update, delete operations) ?      An SQL view is a virtual table that is created by saving the result of a SELECT query. It does not store data itself but presents data from one or more underlying base tables. A view is similar to a table in that you can query it using SELECT statements, apply filtering, sorting, and even joins, just like with a regular table. However, views differ from tables in several key ways. Unlike tables, views do not physically store data, and they cannot have primary keys defined on them. Additionally, while tables fully support INSERT , UPDATE , and DELETE operations, views only support these operations under certain conditions. For example, a view must be updatable—typically meaning it is based on a single table without joins, aggregations, or GROUP BY clauses—to allow data modifications. Even when a view i...

 Class: CST363-30_2253 ( Intro to Database Systems) SQL has the flexibility to join tables on any column(s) using any predicate (=, >, < ).    Most of the time the join will use equality between a primary and foreign key.   Think of example where joining on something other than keys would be needed.  Write the query both as an English sentence and in SQL.  If you can't think of your own example, search the textbook or internet for an example. English Sentence: Imagine you are working with a database that stores information about employees and their salary performance. You may want to find the employees who are earning more than the average salary in their department. In this case, you would join the employee table with the salary data table using the salary amount, not the keys, in order to compare each employee's salary with the department's average. Query:   SELECT e.employee_name, e.department_id, s.salary FROM employees e JOIN salaries ...

  Class: CST363-30_2253 ( Intro to Database Systems) From the orientation, your reading from week 1 and your own experience answer the following questions. Relational database tables and spreadsheets look similar with both having rows and columns.  What are some important differences between the two? A few important differences I can point out between relational database tables and spreadsheets are Data Integrity/Constraints, Data Relationships, and Data Volume/Performance.  Data Integrity/Constraints :  Relational Database  -  Provides tools for ensuring data integrity through constraints like primary keys, foreign keys, and unique constraints. This ensures data is valid, consistent, and adheres to business rules.  Spreadsheets  -  Lack inherent features for enforcing data integrity. It’s easy to accidentally input inconsistent or erroneous data.  Data Relationships :  Relational Database -  Supports complex re...