Chapter 6 – Mapping from Logical ERD to Relational ERD
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Crow’s Foot Notation is the most popular notion used to draw Database Modelling Diagram such as Entity Relationship Diagram (ERD) or Enhanced Entity Relationship Diagram (EERD). Note: 1.Participation/ Association: -The line that connects two entities denotes the participation/ association of two entities -The participation can… Read More
1.Database Forward Engineering Database Forward Engineering is the process to create the Relational Model Diagram or export to a DDL file from a Logical Model Diagram. A Logical Model Diagram contains entities and relationship design for the database. It also contains columns for tables as… Read More
First, we need to know about dependencies 1. Functional Dependencies -Dependency can be understand as one/more attributes depend on other one/more attributes Example: studentid –> (studentname, dob) (semesterid, courseid) –> coursefee 1.1 Functional Dependency (FD): This is the dependency of non-key attributes to key attributes… Read More
1.Index -As we know that PK is the unique constraint in a table. -If we want to make one or more columns that are NOT keys but to be unique. We can create UNIQUE INDEX. Ex: tb1 (c1, c2, c3, c4, c5) –> We have… Read More
1.Entity -By convert the relation, we have entities with attributes in each of entities -In each entities, we can define a Primary Key (PK) for an entity -A weak entity is an entity with a composite key. A weak entity is denoted by double rectangle… Read More
Normalization is the process to normalize (split) a large relation (entity/table) into smaller relations (entities/tables) The Normalization start with a UNF (UnNormalization Form) form. Then, UNF will be processed into 1NF 2NF 3NF BCNF and ERD 1.1NF: First Normalization Form, in this phrase, we will:… Read More
A.System Analysis and Design Tool – Database Design Tool 1.Microsoft Visio – Commercial Software 2.Visual Paradigm – Community version 3.UMLet – Freeware 4.LucidChart – Freeware B.Database Modelling Tool 1.Oracle +Oracle SQL Developer Data Modeler – Freeware 2.MySQL +MySQL WorkBench – Freeware These tools enable to… Read More