Importance of database Constraints
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A constraint can be defined as the property assigned to a column or the set of columns in the database table which prevents inconsistent data values to be stored into the certain columns.
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Constraints are used to ensure the data integrity. This enforce the reliability and accuracy of the data stored in the database.
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In Relational Database Model, There are some Integrity Constraints which are used for accuracy and consistency of data in relational database.
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Data integrity defines some data quality requirements that the data in the database needs to be met.
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The Relational Database Management System will not allow, If a user tries to insert data that doesn’t meet these requirements.
Types of Constraints:
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Entity Integrity constraint (Primary Key (PK) & Unique Key)
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Referential Integrity constraint (Foreign Key (FK))
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Domain Integrity constraint (NOT NULL, DEFAULT and CHECK Constraints)
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