COMPUTER SCIENCE AND ENGINEERING
SQL
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Column
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Constraint
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Index
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Trigger
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Detailed explanation-1: -Constraint defines rules regarding the values allowed in columns and is the standard mechanism for enforcing database integrity. Hence, option (b) Constraint is the correct option.
Detailed explanation-2: -A check constraint (also referred to as a table check constraint) is a database rule that specifies the values allowed in one or more columns of every row of a table.
Detailed explanation-3: -You can also define integrity constraints using the constraint clause of the ALTER TABLE command.
Detailed explanation-4: -Referential Integrity A rule defined on a column (or set of columns) in one table that allows the insert or update of a row only if the value for the column or set of columns (the dependent value) matches a value in a column of a related table (the referenced value).
Detailed explanation-5: -Integrity constraints are defined for tables (not an application) and are stored in the data dictionary. Any data entered by any application must adhere to the same integrity constraints associated with the table.