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The primary key is a critical concept in database design. It uniquely identifies each record in a table and enforces entity integrity. 1. Uniqueness: A primary key ensures that each record in the table has a unique identifier, preventing duplicates. 2. Non-Null Constraint: The primary key field cannot contain null values, ensuring every record is identifiable. 3. Database Operations: Many database operations, such as joins and lookups, rely on the primary key for accurate and efficient processing. 4. Example: In a table of employees, the EmployeeID column can serve as a primary key to uniquely identify every employee. These properties make the primary key indispensable for maintaining data integrity. Why Other Options Are Incorrect: • A) Foreign Key: Establishes a relationship between two tables but does not ensure uniqueness within a table. • B) Composite Key: Comprises two or more columns to uniquely identify a record but is not a primary key unless explicitly defined. • D) Alternate Key: A candidate key not chosen as the primary key, used as an alternate unique identifier. • E) Candidate Key: Represents all fields that can qualify as primary keys but lacks the enforced selection of the primary key.
Method which is specifically recommended for controlling soil erosion in areas with heavy soils and slopes that fall within the range of 11-15%?
Judicious removal of plant part to obtain better and qualitative yield is termed as ___
Khillar is primarily known as a breed for which purpose?
The application of statistical methods to biological experiments is called?
Which one of the following is the data distribution when mean and median values are same?
Which one of the following is not a measure of 'Income-inequality':
_____contributes to the formation and maintenance of root apical meristem.
…………… method helps in maintaining high genetic variability in a population due to repeated intermating of heterozygous plants/populations.
...How much premium will be provided for each 0.1% increase in recovery rate over and above 10.25%?
Chromosome numbers in somatic cells of a maize plant are .........................?