WGU D426 V2 MIDTERM EXAM 2026
QUESTIONS WITH ANSWERS GRADED A+
◉ tuple (Relational Model). Answer: an ordered collection of elements
enclosed in parentheses. Ex: (a, b, c) and (c, b, a) are different, since
tuples are ordered.
◉ Rules (Relational Model). Answer: that govern valid data
◉ table (Relational Model). Answer: has a name, a fixed tuple of
columns, and a varying set of rows.
◉ column (Relational Model). Answer: has a name and a data type.
◉ row (Relational Model). Answer: an unnamed tuple of values. Each
value corresponds to a column and belongs to the column's data type.
◉ data type (Relational Model). Answer: a named set of values, from
which column values are drawn.
◉ Select (Relational Model). Answer: selects a subset of rows of a table.
(Relational operations)
, ◉ Join (Relational Model). Answer: combines two tables by comparing
related columns. (Relational operations)
◉ Union (Relational Model). Answer: selects all rows of two tables
(Relational operations)
◉ Aggregate (Relational Model). Answer: perform a calculation on a set
of values and return a single result. They are commonly used to
summarize or analyze data, such as calculating sums, averages, counts,
or finding maximum or minimum values within a dataset. (Relational
operations)
◉ logical constraints (Relational Model). Answer: Rules that ensure data
is valid (Relational Rules)
◉ Business rules (Relational Model). Answer: e based on business
policy and specific to a particular database.
Ex: PassportNumber values may not repeat in different Employee rows.
◉ Structured Query Language (SQL). Answer: the standard language for
relational databases, and is commonly supported in non-relational
databases.
QUESTIONS WITH ANSWERS GRADED A+
◉ tuple (Relational Model). Answer: an ordered collection of elements
enclosed in parentheses. Ex: (a, b, c) and (c, b, a) are different, since
tuples are ordered.
◉ Rules (Relational Model). Answer: that govern valid data
◉ table (Relational Model). Answer: has a name, a fixed tuple of
columns, and a varying set of rows.
◉ column (Relational Model). Answer: has a name and a data type.
◉ row (Relational Model). Answer: an unnamed tuple of values. Each
value corresponds to a column and belongs to the column's data type.
◉ data type (Relational Model). Answer: a named set of values, from
which column values are drawn.
◉ Select (Relational Model). Answer: selects a subset of rows of a table.
(Relational operations)
, ◉ Join (Relational Model). Answer: combines two tables by comparing
related columns. (Relational operations)
◉ Union (Relational Model). Answer: selects all rows of two tables
(Relational operations)
◉ Aggregate (Relational Model). Answer: perform a calculation on a set
of values and return a single result. They are commonly used to
summarize or analyze data, such as calculating sums, averages, counts,
or finding maximum or minimum values within a dataset. (Relational
operations)
◉ logical constraints (Relational Model). Answer: Rules that ensure data
is valid (Relational Rules)
◉ Business rules (Relational Model). Answer: e based on business
policy and specific to a particular database.
Ex: PassportNumber values may not repeat in different Employee rows.
◉ Structured Query Language (SQL). Answer: the standard language for
relational databases, and is commonly supported in non-relational
databases.
