WGU D426 Questions and Correct Answers/ Latest Update / Already Graded

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WGU D426 Questions and Correct
Answers/ Latest Update / Already
Graded
A ____ is a column, or group of columns, used to identify a row.


Ans: Primary key




A ____ consists of a single column.


Ans: Simple primary key




A ____ key consists of multiple columns.


Ans: Composite primary




All primary keys columns are necessary for uniqueness. When any

column is removed, the resulting simple or composite column is no

longer unique.


Ans: Minimal

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The ____ constraint in the CREATE TABLE statement names the table's

____. The ____ constraint ensures that a column or group of columns

is always unique and non-null.


Ans: Primary key




An _____ is a numeric column that is assigned an automatically

incrementing value when a new row is inserted.


Ans: Auto-increment column




The ____ keyword defines an auto-increment column. It follows the

column's data type in a CREATE TABLE statement.


Ans: AUTO_INCREMENT




A ____ is a column, or group of columns, that refer to a primary key.


Ans: Foreign key

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____ requires foreign key values must either be NULL or match some

value of the referenced primary key.


Ans: Referential integrity




A ____ constraint is added to a CREATE TABLE statement with the ____

and REFERENCES keywords.


Ans: Foreign key; references




A ____ foreign key is a simple or composite foreign key in which all

columns are NULL.


Ans: Fully NULL




____ is a relational rule that requires foreign key values to either be

fully NULL or match some primary key value.


Ans: Referential integrity