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WGU D426 Questions with Answers (100% Correct
Answers
A ____ is a column, or group of columns, used to identify a row.
Answer: Primary key
A ____ consists of a single column. Answer: Simple primary key
A ____ key consists of multiple columns. Answer: 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. Answer: Minimal
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. Answer: Primary key
An _____ is a numeric column that is assigned an automatically
incrementing value when a new row is inserted. Answer: Auto-
increment column
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The ____ keyword defines an auto-increment column. It follows the
column's data type in a CREATE TABLE statement. Answer:
AUTO_INCREMENT
A ____ is a column, or group of columns, that refer to a primary key.
Answer: Foreign key
____ requires foreign key values must either be NULL or match some
value of the referenced primary key. Answer: Referential integrity
A ____ constraint is added to a CREATE TABLE statement with the
____ and REFERENCES keywords. Answer: Foreign key; references
A ____ foreign key is a simple or composite foreign key in which all
columns are NULL. Answer: Fully NULL
____ is a relational rule that requires foreign key values to either be
fully NULL or match some primary key value. Answer: Referential
integrity
____ rejects an insert, update, or delete that violates referential
integrity. Answer: RESTRICT
____ sets invalid foreign keys to NULL. Answer: SET NULL
© 2025 All rights reserved
WGU D426 Questions with Answers (100% Correct
Answers
A ____ is a column, or group of columns, used to identify a row.
Answer: Primary key
A ____ consists of a single column. Answer: Simple primary key
A ____ key consists of multiple columns. Answer: 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. Answer: Minimal
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. Answer: Primary key
An _____ is a numeric column that is assigned an automatically
incrementing value when a new row is inserted. Answer: Auto-
increment column
© 2025 All rights reserved
, 2
The ____ keyword defines an auto-increment column. It follows the
column's data type in a CREATE TABLE statement. Answer:
AUTO_INCREMENT
A ____ is a column, or group of columns, that refer to a primary key.
Answer: Foreign key
____ requires foreign key values must either be NULL or match some
value of the referenced primary key. Answer: Referential integrity
A ____ constraint is added to a CREATE TABLE statement with the
____ and REFERENCES keywords. Answer: Foreign key; references
A ____ foreign key is a simple or composite foreign key in which all
columns are NULL. Answer: Fully NULL
____ is a relational rule that requires foreign key values to either be
fully NULL or match some primary key value. Answer: Referential
integrity
____ rejects an insert, update, or delete that violates referential
integrity. Answer: RESTRICT
____ sets invalid foreign keys to NULL. Answer: SET NULL
© 2025 All rights reserved
