WGU - D426 Exam; Questions and Answers 100% Correct

WGU - D426 Exam ; Questions and Answers 100% Correct A ____ is a column, or group of columns, used to identify a row. Correct answer Primary key A ____ consists of a single column. Correct answer Simple primary key A ____ key consists of multiple columns. Correct 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. Correct 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. Correct answer Primary key An _____ is a numeric column that is assigned an automatically incrementing value when a new row is inserted. Correct answer Auto -increment column The ____ keyword defines an auto -increment column. It follows the column's data type in a CREATE TABLE statement. Correct answer AUTO_INCREMENT A ____ is a column, or group of columns, that refer to a primary key. Correct answer Foreign key ____ requires foreign key values must either be NULL or match some value of the referenced primary key. Correct answer Referential integrity A ____ constraint is added to a CREATE TABLE statement with the ____ and REFERENCES keywords. Correct answer Foreign key; references WGU - D426 Exam ; Questions and Answers 100% Correct A ____ foreign key is a simple or composite foreign key in which all columns are NULL. Correct answer Fully NULL ____ is a relational rule that requires foreign key values to either be fully NULL or match some primary key value. Correct answer Referential integrity ____ rejects an insert, update, or delete that violates referential integrity. Correct answer RESTRICT ____ sets invalid foreign keys to NULL. Correct answer SET NULL ____ sets invalid foreign keys to the foreign key default value. Correct answer SET DEFAULT ____ propagates primary key changes to foreign keys. Correct answer 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. Correct answer 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 database automatically rejects insert, update, and delete statements that violate a constraint. Correct answer Constraint(s) A ____ appears after the column name and data type in a CREATE TABLE statement. Column constraints govern values in a single column. Correct answer Column constraint