Chapter 1 (English)

4. Table Structure in DBMS

A table is a two-dimensional structure in a database that stores data in the form of rows (tuples) and columns (attributes).

• Each row represents one record.
• Each column represents a specific data field.

2. Components of a Table

• Table Name → Unique name to identify the table (e.g., Students).
• Attributes (Columns) → Data fields (e.g., StudentID, Name, Age).
• Tuples (Rows) → Actual data entries (e.g., one student’s record).
• Degree → Number of attributes (columns).
• Cardinality → Number of tuples (rows).
• Domain → Allowed values for each attribute (e.g., Age must be an integer).
• Constraints → Rules to maintain data consistency (Primary Key, Foreign Key, Not Null, Unique, Check).

  3. Key Points (Quick Recap)

• Table = Rows + Columns
• Row = Record (tuple)
• Column = Attribute (field)
• Degree = Number of columns
• Cardinality = Number of rows
• Constraints = Rules that ensure correctness and uniqueness of data