Cconstraint In Dbms

Here are key points describing constraints in a Database Management System (DBMS):

  • Purpose: Constraints are rules enforced on data columns to maintain the accuracy and integrity of the information within a database.
  • Data Validation: They ensure that data entered into the database adheres to predefined conditions and formats, preventing invalid or erroneous data.
  • Consistency: Constraints help maintain consistency across the database, especially when multiple users are accessing and modifying data simultaneously.
  • Relationship Enforcement: They define and enforce relationships between tables, ensuring referential integrity (e.g., preventing deletion of a record if it’s referenced by another table).
  • Types Include: Common types are PRIMARY KEY (unique identifier), FOREIGN KEY (links tables), NOT NULL (ensures a column is not empty), UNIQUE (all values in a column are distinct), and CHECK (ensures values meet a specific condition).
  • Data Control: They restrict unauthorized or illogical data modifications, protecting the database’s reliability.

          

constaint in dbms Dbms