1 / 11

CS 101 – Nov. 11

CS 101 – Nov. 11. Finish Database concepts 1-1 relationship 1-many relationship Many-to-many relationship Review. Relationships. When you have 2+ tables, there is almost always a relationship They share one field in common. Can you tell what it is? Ex. Customers & Orders

dlugo
Télécharger la présentation

CS 101 – Nov. 11

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. CS 101 – Nov. 11 • Finish Database concepts • 1-1 relationship • 1-many relationship • Many-to-many relationship • Review

  2. Relationships • When you have 2+ tables, there is almost always a relationship • They share one field in common. • Can you tell what it is? • Ex. Customers & Orders • Ex. Publishers & books

  3. One-to-One • Can be useful if some information is confidential. • What if we didn’t have any relationship?

  4. 1-1 Query • When you combine tables that have a 1-1 relationship: Access will look for fields that are the same, and use this as a filter. • In previous example, we’ll have 2 results instead of 4.  Employee 101’s information Employee 102’s information • Let’s look at another example.

  5. What happens when we “join” these 1-1 tables?

  6. Example

  7. Referential integrity Keep related records consistent Cascade delete: allow deletion of “one” Cascade update: allow update of “one” For example, changing someone’s CustomerID. One-many Relationships

  8. Many-to-many • Ex. Customers to products • Implement as 2 one-to-one • “Order details” table • Think of possible queries based on the 5 tables given in handout.

  9. Outline for test • Excel • text functions, scenarios, solver, goal seek (Chapter 5) • Problem solving / software • Look at contents of Python folder • Text software • Database • Tables, relationships, queries, reports

  10. Problem solving/software • Steps in solving problems • Types of languages & statements • Variables • Example algorithms & programs: search, sum, sort • Kinds of bugs & how to fix them • Operating systems • Various responsibilities • Scheduling • File system issues • 4 ways to search for data

More Related