WGU D426 EXAM 2025/2026 QUESTIONS
AND ANSWERS 100% PASS
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
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
1 @COPYRIGHT 2025/2026.
, A ____ is a column, or group of columns, that refer to a primary key. - ANS Foreign key
____ 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
____ rejects an insert, update, or delete that violates referential integrity. - ANS RESTRICT
____ sets invalid foreign keys to NULL. - ANS SET NULL
____ sets invalid foreign keys to the foreign key default value. - ANS SET DEFAULT
____ propagates primary key changes to foreign keys. - ANS CASCADE
Actions are specified in the optional ____ and ____ clauses of the FOREIGN KEY constraint.
____ and ____ are followed by either RESTRICT, SET NULL, SET DEFAULT, or CASCADE. -
ANS ON UPDATE and ON DELETE
A ____ is a rule that governs allowable values in a database. ____ are based on relational and
business rules, and implemented with special keywords in a CREATE TABLE statement. The
2 @COPYRIGHT 2025/2026.
AND ANSWERS 100% PASS
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
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
1 @COPYRIGHT 2025/2026.
, A ____ is a column, or group of columns, that refer to a primary key. - ANS Foreign key
____ 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
____ rejects an insert, update, or delete that violates referential integrity. - ANS RESTRICT
____ sets invalid foreign keys to NULL. - ANS SET NULL
____ sets invalid foreign keys to the foreign key default value. - ANS SET DEFAULT
____ propagates primary key changes to foreign keys. - ANS CASCADE
Actions are specified in the optional ____ and ____ clauses of the FOREIGN KEY constraint.
____ and ____ are followed by either RESTRICT, SET NULL, SET DEFAULT, or CASCADE. -
ANS ON UPDATE and ON DELETE
A ____ is a rule that governs allowable values in a database. ____ are based on relational and
business rules, and implemented with special keywords in a CREATE TABLE statement. The
2 @COPYRIGHT 2025/2026.
