Rdbms session 01_a
- 1. Introduction to Relational Database Management Systems Rationale Database is an integral part of an organization. Aspiring database developers should be able to efficiently design and implement databases. Knowledge of these will enable the developers to build robust database solutions. This module will help students to understand the concepts related to relational databases. Ver. 1.0 Slide 1 of 31
- 2. Introduction to Relational Database Management Systems Objectives In this session, you will learn to: Define a database management system Describe the types of data models Ver. 1.0 Slide 2 of 31
- 3. Introduction to Relational Database Management Systems Database Management Systems What is a database? Ver. 1.0 Slide 3 of 31
- 4. Introduction to Relational Database Management Systems Database Management Systems (Contd.) A database is a collection of logically related data. Data means known facts, which are meaningful and can be recorded. For example: Address Book Hard Disk Ver. 1.0 Slide 4 of 31
- 5. Introduction to Relational Database Management Systems Database Management Systems (Contd.) Database Management Systems (DBMS) is the software required to perform the task of maintaining databases. Management of data involves: Defining structures for data storage. Providing methods for data manipulation, such as adding, editing, and deleting data. Providing data security against unauthorized access. Ver. 1.0 Slide 5 of 31
- 6. Introduction to Relational Database Management Systems Database Management Systems (Contd.) The main objectives of any DBMS are to: Provide an efficient and easy way to store, update, and retrieve data from a database. Manage information about users who interact with the DBMS, and the tasks that these users can perform on the data. Ver. 1.0 Slide 6 of 31
- 7. Introduction to Relational Database Management Systems Database Management Systems (Contd.) Now, let us understand the working of DBMS. Ver. 1.0 Slide 7 of 31
- 8. Introduction to Relational Database Management Systems Database Management Systems (Contd.) User system to extract information from the database Request for Retrieved data data returned as a result DBMS Database Ver. 1.0 Slide 8 of 31
- 9. Introduction to Relational Database Management Systems Data Models What is a data model? Ver. 1.0 Slide 9 of 31
- 10. Introduction to Relational Database Management Systems Data Models (Contd.) A data model is a description of the data in a database. Data models can be broadly classified into the following categories: Object-based logical model: Focuses on describing the data, the relationship among the data, and any constraints defined. Record-based logical model: Focuses on specifying the logical structuring of the database. Ver. 1.0 Slide 10 of 31
- 11. Introduction to Relational Database Management Systems Object-Based Logical Model Let us understand the object-based logical model. Ver. 1.0 Slide 11 of 31
- 12. Introduction to Relational Database Management Systems Object-Based Logical Model (Contd.) The ER model: Views the real world as a collection of objects or entities and the relationship among them. Has a corresponding diagramming technique. Ver. 1.0 Slide 12 of 31
- 13. Introduction to Relational Database Management Systems Object-Based Logical Model (Contd.) The following diagram shows various components and depicts the relationship between them. Attributes Attributes Relationship Entities Ver. 1.0 Slide 13 of 31
- 14. Introduction to Relational Database Management Systems Object-Based Logical Model (Contd.) An entity: Is any object, place, person, or activity about which the data is recorded. Can be categorized as entity type and entity instance. In the ER model diagramming technique, entities are named and represented inside a box. For example: Ver. 1.0 Slide 14 of 31
- 15. Introduction to Relational Database Management Systems Object-Based Logical Model (Contd.) Entity can be of the following types: Dependent entity: Depends on another entity for existence. Is also called as a weak entity. Independent entity: Does not depend on any other entity for existence. Is also called as a regular entity. The following diagram consists of an entity, OFFERING, which is dependent on an entity, COURSE. Independent Entity Dependent Entity Ver. 1.0 Slide 15 of 31
- 16. Introduction to Relational Database Management Systems Object-Based Logical Model (Contd.) Chen defined a relationship as “an association among entities”. A relationship is depicted as a diamond with the name of the relationship type. For example: Relationship Ver. 1.0 Slide 16 of 31
- 17. Introduction to Relational Database Management Systems Object-Based Logical Model (Contd.) The following diagram represents the association of an entity with itself. STUDENT SEMINAR An entity associating with itself can be a student giving a seminar presentation to other students. Ver. 1.0 Slide 17 of 31
- 18. Introduction to Relational Database Management Systems Object-Based Logical Model (Contd.) The following diagram represents multiple relationships between the entities, TEACHER and STUDENT. Ver. 1.0 Slide 18 of 31
- 19. Introduction to Relational Database Management Systems Just a minute The following statement has been extracted from a case presented by a manufacturer regarding the maintenance of their data: “A supplier ships certain parts”. Identify the entities mentioned in this statement, and their relationship. Draw a diagram depicting the relationship. Solution: Entities: SUPPLIER, PARTS Relationship: SHIP or SUPPLIES Ver. 1.0 Slide 19 of 31
- 20. Introduction to Relational Database Management Systems Object-Based Logical Model (Contd.) There are three types of relationships: One-to-one One-to-many (or Many-to-one) Many-to-many Ver. 1.0 Slide 20 of 31
- 21. Introduction to Relational Database Management Systems Object-Based Logical Model (Contd.) The following diagram represents the one-to-one relationship between DEPARTMENT and DEPARTMENT HEAD. For a particular DEPARTMENT there can be only one DEPARTMENT HEAD. Ver. 1.0 Slide 21 of 31
- 22. Introduction to Relational Database Management Systems Object-Based Logical Model (Contd.) The following diagram represents the many-to-one relationship between STUDENT and MAJOR. A STUDENT can MAJOR in only one course, but many STUDENTs can register for a given MAJOR course. Ver. 1.0 Slide 22 of 31
- 23. Introduction to Relational Database Management Systems Object-Based Logical Model (Contd.) The following diagram represents the many-to-many relationship between STUDENT and COURSE. A STUDENT can take many COURSEs and many STUDENTs can register for a given COURSE. Ver. 1.0 Slide 23 of 31
- 24. Introduction to Relational Database Management Systems Just a minute What do the following ER diagrams represent? Solution: Many students can work on many projects. Many employees belong to only one department. Ver. 1.0 Slide 24 of 31
- 25. Introduction to Relational Database Management Systems Just a minute Consider the following statement of a manufacturing company: “A supplier supplies certain parts. A particular part is not necessarily supplied by only one supplier. No supplier supplies only a single part.” What type of relationship is this? Draw a diagram to depict the relationship. Solution: Many-to-many relationship Ver. 1.0 Slide 25 of 31
- 26. Introduction to Relational Database Management Systems Object-Based Logical Model (Contd.) An attribute: Is a property of a given entity. Is depicted as ellipses, labeled with the name of the property. The following diagram shows the various attributes of the entity, STUDENT. Ver. 1.0 Slide 26 of 31
- 27. Introduction to Relational Database Management Systems Just a minute A manufacturer needs to maintain the following details about the supplier: Name Address Credit status Assigned code number Draw a diagram to depict this information. Solution: Ver. 1.0 Slide 27 of 31
- 28. Introduction to Relational Database Management Systems Object-Based Logical Model (Contd.) A subtype: Is a subset of another entity. Is always dependent on the supertype for its existence. The attributes of a supertype apply to all of its subtypes. Ver. 1.0 Slide 28 of 31
- 29. Introduction to Relational Database Management Systems Object-Based Logical Model (Contd.) The following diagram shows the relationship between supertype (COURSE) and subtypes (STANDLONE and SEMESTER). The supertype is connected to the relationship with a line containing a crossbar. Ver. 1.0 Slide 29 of 31
- 30. Introduction to Relational Database Management Systems Just a minute There are two types of suppliers. One type of supplier allows credit, while the other type insists on payment in cash before delivery. The manufacturer wishes to maintain separate information on these two types of suppliers. For the credit supplier, “credit period” and “credit limit” have to be recorded. For the cash supplier, “date of payment” has to be stored. Represent this information diagrammatically. Solution: Ver. 1.0 Slide 30 of 31
- 31. Introduction to Relational Database Management Systems Summary In this session, you learned that: Data models can be classified as: Object-based logical model Record-based logical model In the ER diagramming technique: Entities are represented as rectangles. Relationships are represented as diamonds. Attributes are represented as ellipses. Relationships, whether many-to-many, one-to-many, or one-to-one are represented symbolically. Weak entities are represented by double-lined boxes. Subtypes are connected to the supertype by an unnamed relationship, marked with a crossbar on top. Ver. 1.0 Slide 31 of 31
Editor's Notes
- #5: Student already have learnt about type 2 SCDs in Module I. Therefore, you can start this topic by asking the following questions to students: What are type 2 SCDs? Given an example to explain type 2 SCDs. This will recapitulate what they have learnt about type 2 SCD in Module 1. Now explain the strategy to update the data into these dimension tables with help the example given in SG. After explaining the examples, you can ask students to think of an example of a type 2 SCD and then tell the strategy to update the data into this dimension table.
- #6: Student already have learnt about type 2 SCDs in Module I. Therefore, you can start this topic by asking the following questions to students: What are type 2 SCDs? Given an example to explain type 2 SCDs. This will recapitulate what they have learnt about type 2 SCD in Module 1. Now explain the strategy to update the data into these dimension tables with help the example given in SG. After explaining the examples, you can ask students to think of an example of a type 2 SCD and then tell the strategy to update the data into this dimension table.
- #7: You can summarize the session by running through the summary given in SG. In addition, you can also ask students summarize what they have learnt in this session.
- #9: You can summarize the session by running through the summary given in SG. In addition, you can also ask students summarize what they have learnt in this session.
- #11: Student already have learnt about type 2 SCDs in Module I. Therefore, you can start this topic by asking the following questions to students: What are type 2 SCDs? Given an example to explain type 2 SCDs. This will recapitulate what they have learnt about type 2 SCD in Module 1. Now explain the strategy to update the data into these dimension tables with help the example given in SG. After explaining the examples, you can ask students to think of an example of a type 2 SCD and then tell the strategy to update the data into this dimension table.
- #13: Student already have learnt about type 2 SCDs in Module I. Therefore, you can start this topic by asking the following questions to students: What are type 2 SCDs? Given an example to explain type 2 SCDs. This will recapitulate what they have learnt about type 2 SCD in Module 1. Now explain the strategy to update the data into these dimension tables with help the example given in SG. After explaining the examples, you can ask students to think of an example of a type 2 SCD and then tell the strategy to update the data into this dimension table.
- #14: Student already have learnt about type 2 SCDs in Module I. Therefore, you can start this topic by asking the following questions to students: What are type 2 SCDs? Given an example to explain type 2 SCDs. This will recapitulate what they have learnt about type 2 SCD in Module 1. Now explain the strategy to update the data into these dimension tables with help the example given in SG. After explaining the examples, you can ask students to think of an example of a type 2 SCD and then tell the strategy to update the data into this dimension table.
- #15: Student already have learnt about type 2 SCDs in Module I. Therefore, you can start this topic by asking the following questions to students: What are type 2 SCDs? Given an example to explain type 2 SCDs. This will recapitulate what they have learnt about type 2 SCD in Module 1. Now explain the strategy to update the data into these dimension tables with help the example given in SG. After explaining the examples, you can ask students to think of an example of a type 2 SCD and then tell the strategy to update the data into this dimension table.
- #16: Student already have learnt about type 2 SCDs in Module I. Therefore, you can start this topic by asking the following questions to students: What are type 2 SCDs? Given an example to explain type 2 SCDs. This will recapitulate what they have learnt about type 2 SCD in Module 1. Now explain the strategy to update the data into these dimension tables with help the example given in SG. After explaining the examples, you can ask students to think of an example of a type 2 SCD and then tell the strategy to update the data into this dimension table.
- #17: Student already have learnt about type 2 SCDs in Module I. Therefore, you can start this topic by asking the following questions to students: What are type 2 SCDs? Given an example to explain type 2 SCDs. This will recapitulate what they have learnt about type 2 SCD in Module 1. Now explain the strategy to update the data into these dimension tables with help the example given in SG. After explaining the examples, you can ask students to think of an example of a type 2 SCD and then tell the strategy to update the data into this dimension table.
- #18: Student already have learnt about type 2 SCDs in Module I. Therefore, you can start this topic by asking the following questions to students: What are type 2 SCDs? Given an example to explain type 2 SCDs. This will recapitulate what they have learnt about type 2 SCD in Module 1. Now explain the strategy to update the data into these dimension tables with help the example given in SG. After explaining the examples, you can ask students to think of an example of a type 2 SCD and then tell the strategy to update the data into this dimension table.
- #19: Student already have learnt about type 2 SCDs in Module I. Therefore, you can start this topic by asking the following questions to students: What are type 2 SCDs? Given an example to explain type 2 SCDs. This will recapitulate what they have learnt about type 2 SCD in Module 1. Now explain the strategy to update the data into these dimension tables with help the example given in SG. After explaining the examples, you can ask students to think of an example of a type 2 SCD and then tell the strategy to update the data into this dimension table.
- #20: Student already have learnt about type 2 SCDs in Module I. Therefore, you can start this topic by asking the following questions to students: What are type 2 SCDs? Given an example to explain type 2 SCDs. This will recapitulate what they have learnt about type 2 SCD in Module 1. Now explain the strategy to update the data into these dimension tables with help the example given in SG. After explaining the examples, you can ask students to think of an example of a type 2 SCD and then tell the strategy to update the data into this dimension table.
- #21: Student already have learnt about type 2 SCDs in Module I. Therefore, you can start this topic by asking the following questions to students: What are type 2 SCDs? Given an example to explain type 2 SCDs. This will recapitulate what they have learnt about type 2 SCD in Module 1. Now explain the strategy to update the data into these dimension tables with help the example given in SG. After explaining the examples, you can ask students to think of an example of a type 2 SCD and then tell the strategy to update the data into this dimension table.
- #22: Student already have learnt about type 2 SCDs in Module I. Therefore, you can start this topic by asking the following questions to students: What are type 2 SCDs? Given an example to explain type 2 SCDs. This will recapitulate what they have learnt about type 2 SCD in Module 1. Now explain the strategy to update the data into these dimension tables with help the example given in SG. After explaining the examples, you can ask students to think of an example of a type 2 SCD and then tell the strategy to update the data into this dimension table.
- #23: Student already have learnt about type 2 SCDs in Module I. Therefore, you can start this topic by asking the following questions to students: What are type 2 SCDs? Given an example to explain type 2 SCDs. This will recapitulate what they have learnt about type 2 SCD in Module 1. Now explain the strategy to update the data into these dimension tables with help the example given in SG. After explaining the examples, you can ask students to think of an example of a type 2 SCD and then tell the strategy to update the data into this dimension table.
- #24: Student already have learnt about type 2 SCDs in Module I. Therefore, you can start this topic by asking the following questions to students: What are type 2 SCDs? Given an example to explain type 2 SCDs. This will recapitulate what they have learnt about type 2 SCD in Module 1. Now explain the strategy to update the data into these dimension tables with help the example given in SG. After explaining the examples, you can ask students to think of an example of a type 2 SCD and then tell the strategy to update the data into this dimension table.
- #25: Student already have learnt about type 2 SCDs in Module I. Therefore, you can start this topic by asking the following questions to students: What are type 2 SCDs? Given an example to explain type 2 SCDs. This will recapitulate what they have learnt about type 2 SCD in Module 1. Now explain the strategy to update the data into these dimension tables with help the example given in SG. After explaining the examples, you can ask students to think of an example of a type 2 SCD and then tell the strategy to update the data into this dimension table.
- #26: Student already have learnt about type 2 SCDs in Module I. Therefore, you can start this topic by asking the following questions to students: What are type 2 SCDs? Given an example to explain type 2 SCDs. This will recapitulate what they have learnt about type 2 SCD in Module 1. Now explain the strategy to update the data into these dimension tables with help the example given in SG. After explaining the examples, you can ask students to think of an example of a type 2 SCD and then tell the strategy to update the data into this dimension table.
- #27: Student already have learnt about type 2 SCDs in Module I. Therefore, you can start this topic by asking the following questions to students: What are type 2 SCDs? Given an example to explain type 2 SCDs. This will recapitulate what they have learnt about type 2 SCD in Module 1. Now explain the strategy to update the data into these dimension tables with help the example given in SG. After explaining the examples, you can ask students to think of an example of a type 2 SCD and then tell the strategy to update the data into this dimension table.
- #28: Student already have learnt about type 2 SCDs in Module I. Therefore, you can start this topic by asking the following questions to students: What are type 2 SCDs? Given an example to explain type 2 SCDs. This will recapitulate what they have learnt about type 2 SCD in Module 1. Now explain the strategy to update the data into these dimension tables with help the example given in SG. After explaining the examples, you can ask students to think of an example of a type 2 SCD and then tell the strategy to update the data into this dimension table.
- #29: Student already have learnt about type 2 SCDs in Module I. Therefore, you can start this topic by asking the following questions to students: What are type 2 SCDs? Given an example to explain type 2 SCDs. This will recapitulate what they have learnt about type 2 SCD in Module 1. Now explain the strategy to update the data into these dimension tables with help the example given in SG. After explaining the examples, you can ask students to think of an example of a type 2 SCD and then tell the strategy to update the data into this dimension table.
- #30: Student already have learnt about type 2 SCDs in Module I. Therefore, you can start this topic by asking the following questions to students: What are type 2 SCDs? Given an example to explain type 2 SCDs. This will recapitulate what they have learnt about type 2 SCD in Module 1. Now explain the strategy to update the data into these dimension tables with help the example given in SG. After explaining the examples, you can ask students to think of an example of a type 2 SCD and then tell the strategy to update the data into this dimension table.
- #31: Student already have learnt about type 2 SCDs in Module I. Therefore, you can start this topic by asking the following questions to students: What are type 2 SCDs? Given an example to explain type 2 SCDs. This will recapitulate what they have learnt about type 2 SCD in Module 1. Now explain the strategy to update the data into these dimension tables with help the example given in SG. After explaining the examples, you can ask students to think of an example of a type 2 SCD and then tell the strategy to update the data into this dimension table.
- #32: You can summarize the session by running through the summary given in SG. In addition, you can also ask students summarize what they have learnt in this session.