WGU D426 V2 EXAM SCRIPT TESTED
QUESTIONS WITH VERIFIED ANSWERS
PRACTICE SOLUTION GRADED A+
⩥ INSERT Statement (Syntax).
Answer: INSERT [INTO] TableName (Column1, Column2, ...)VALUES
(Value1, Value2, ...);
⩥ UPDATE Statement (Clauses).
Answer: Uses the SET clause to specify the new column values.
An optional WHERE clause specifies which rows are updated.
Omitting the WHERE clause results in all rows being updated.
⩥ DELETE Statement (Keywords/Clauses).
Answer: The FROM keyword is followed by the table name whose rows
are to be deleted.
An optional WHERE clause specifies which rows should be deleted.
Omitting the WHERE clause results in all rows in the table being
deleted.
⩥ TRUNCATE Statement.
Answer: Deletes all rows from a table.
,⩥ Primary Key.
Answer: A _______ ___ is a constraint on a column, or group of
columns, used to identify a row. The ________ ____ is usually the
table's first column and appears on the left of table diagrams, but the
position is not significant to the database. A solid circle (●) notates these
in table diagrams.
MUST BE "Unique" and "Not NULL"
⩥ Simple Primary Key.
Answer: A key that consists of a SINGLE column.
⩥ Composite Key.
Answer: A key that consists of multiple columns and is denoted with
parenthesis.
MUST BE Minimal, meaning only NECESSARY primary keys may be
involved. In it's minimal stage, if one of these keys is removed it then
becomes no longer unique.
⩥ Auto-Increment.
Answer: Database users occasionally make the following errors when
inserting primary keys:
, Inserting values for auto-increment primary keys.
Omitting values for primary keys that are not auto-increment columns.
MySQL allows insertion of a specific value to an auto-increment
column. However, overriding auto-increment for a primary key is
usually a mistake.
⩥ Foreign Key.
Answer: Is a column, or group of columns, that refer to a primary key.
An empty circle (○) represents foreign keys in table diagrams, and an
arrow leads to the referenced primary key.
When a ________ _____ constraint is specified, the database rejects
insert, update, and delete statements that violate referential integrity.
Referential integrity requires ________ ____ values must either be
NULL or match some value of the referenced primary key.
⩥ RESTRICT.
Answer: ________ rejects an insert, update, or delete that violates
referential integrity.
⩥ CASCADE.
Answer: Propagates primary key changes to foreign keys.
QUESTIONS WITH VERIFIED ANSWERS
PRACTICE SOLUTION GRADED A+
⩥ INSERT Statement (Syntax).
Answer: INSERT [INTO] TableName (Column1, Column2, ...)VALUES
(Value1, Value2, ...);
⩥ UPDATE Statement (Clauses).
Answer: Uses the SET clause to specify the new column values.
An optional WHERE clause specifies which rows are updated.
Omitting the WHERE clause results in all rows being updated.
⩥ DELETE Statement (Keywords/Clauses).
Answer: The FROM keyword is followed by the table name whose rows
are to be deleted.
An optional WHERE clause specifies which rows should be deleted.
Omitting the WHERE clause results in all rows in the table being
deleted.
⩥ TRUNCATE Statement.
Answer: Deletes all rows from a table.
,⩥ Primary Key.
Answer: A _______ ___ is a constraint on a column, or group of
columns, used to identify a row. The ________ ____ is usually the
table's first column and appears on the left of table diagrams, but the
position is not significant to the database. A solid circle (●) notates these
in table diagrams.
MUST BE "Unique" and "Not NULL"
⩥ Simple Primary Key.
Answer: A key that consists of a SINGLE column.
⩥ Composite Key.
Answer: A key that consists of multiple columns and is denoted with
parenthesis.
MUST BE Minimal, meaning only NECESSARY primary keys may be
involved. In it's minimal stage, if one of these keys is removed it then
becomes no longer unique.
⩥ Auto-Increment.
Answer: Database users occasionally make the following errors when
inserting primary keys:
, Inserting values for auto-increment primary keys.
Omitting values for primary keys that are not auto-increment columns.
MySQL allows insertion of a specific value to an auto-increment
column. However, overriding auto-increment for a primary key is
usually a mistake.
⩥ Foreign Key.
Answer: Is a column, or group of columns, that refer to a primary key.
An empty circle (○) represents foreign keys in table diagrams, and an
arrow leads to the referenced primary key.
When a ________ _____ constraint is specified, the database rejects
insert, update, and delete statements that violate referential integrity.
Referential integrity requires ________ ____ values must either be
NULL or match some value of the referenced primary key.
⩥ RESTRICT.
Answer: ________ rejects an insert, update, or delete that violates
referential integrity.
⩥ CASCADE.
Answer: Propagates primary key changes to foreign keys.
