How Relational Database Model Work?
The relational database, created by IBM’s E.F. Codd in the 1970s, enables any table to be associated to another table by means of a common attribute. Codd suggested a change to a data model where data is stored, accessed, and related in tables without restructuring the tables that hold them in place of hierarchical structures.
Each spreadsheet in the relational database model is a table that contains data, which is shown as rows (records or tuples) and columns (attributes).
A data type is specified by an attribute (column), and the value of that particular data type is contained in each record (or row). A primary key is an attribute found in all tables in a relational database that serves as a unique row identifier. Let’s take an example.
Example: The following table STUDENT consists of three columns Roll Number, Name, Section and four records of students 1, 2, 3 and 4 respectively. The records can’t be completely same, the Roll Number acts as a candidate key which separates records.
Roll number | Name | Section |
---|---|---|
1 | Ishita | A |
2 | Yash | B |
3 | Ishita | A |
4 | Mallika | C |
RDBMS Full Form
A database is an organized collection of data stored in a computer system and usually controlled by a database management system (DBMS). The data in common databases is modeled in tables, making querying and processing efficient.
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