Introduction To Database New Edition By Asif Iqbal

Lecture -2

Relations • One-to-one • One-to-many • Many-to-many gtvc. eu 5. org aiseries

One-to-one (Relationship) • • one record in a table is associated with one and only one record in another table. For example, in a school database, each student has only one student ID, and each student ID is assigned to only one person Student Name 1 1 gtvc. eu 5. org Reg-No aiseries

One-to-many (Relationship) • • In a one-to-many relationship, one record in a table can be associated with one or more records in another table. For example, each customer can have many sales orders Customers M 1 gtvc. eu 5. org Orders aiseries

Many-to-many (Relationship) • Refers to the relationship between two entities A and B in which A may contain a parent instance for which there are many children in B and vice versa. Authors N M gtvc. eu 5. org Books aiseries

Database (Types) • • Operational Database (SADB) Analytical Database Data Warehouse Distributed Database End User Database External Database Text Database Image and Multimedia Database gtvc. eu 5. org aiseries

DBMS • • Database Management System Acts as a repository for all data and is responsible for • • Storage Security Integrity Concurrency Recovery Access It has Data-dictionary (Catalog) which stores structure, location, and types of data. gtvc. eu 5. org aiseries

Lecture -2 (Summing Up) gtvc. eu 5. org aiseries