DATABASE MODELING AND DATABASE SYSTEMS
DLBCSMDS01 – Q&A
Unit 1
Q1 - The term database management system...
refers to systems that can be used to manage relational databases.
Q2 - In tables of relational databases...
a column corresponds to an attribute.
Q3 - In relational databases,...
you can distribute data for a complex object across several tables.
Q4 - Which of the following statements is correct?
Tables contain entity sets.
Q5 - A primary key...
must never have the value NULL.
Unit 2
Q1 - The SQL command SELECT...
reads data from a database, but does not change its contents.
Q2 - The command SELECT X,Y FROM Address...
outputs a virtual table with 2 columns.
Q3 - The ORDER BY element in the SQL command SELECT...
enables a clearer output of the result table.
, Q4 - The GROUP BY element in the SQL command SELECT...
can be used when evaluations of groups of data records are required.
Q5 - Which of the following statements about the SQL command SELECT X,V FROM Y WHERE Z>2
GROUP BY V HAVING COUNT()<3 is correct?
This command cannot be executed because it contains a syntax error.
Unit 3
Q1 - The graphical representation of E/R diagrams...
can be done with UML notation. In this case, the UML class diagram is used.
Q2 - Which of the following statements is correct regarding the following relationship: “A vendor
delivers at least one article and each article is delivered by no or exactly one vendor”?
It is a relationship that cannot be represented by Chen notation.
Q3 - Which of the following statements is correct regarding the following relationship: “A band
gives at least one concert and at each concert at least one band plays”?
This is an N:M relationship.
Q4 - The first normal form for tables in relational databases...
is the basis for the transition to a higher normal form.
Q5 - The second normal form for tables in relational databases...
requires, among other things, the fulfilment of all conditions required for the 1st normal form.
Unit 4
Q1 - Which of the following statements on the logical design of relational databases is correct?
Normalization often leads to several additional foreign key relationships for which consistency
conditions must be created.
DLBCSMDS01 – Q&A
Unit 1
Q1 - The term database management system...
refers to systems that can be used to manage relational databases.
Q2 - In tables of relational databases...
a column corresponds to an attribute.
Q3 - In relational databases,...
you can distribute data for a complex object across several tables.
Q4 - Which of the following statements is correct?
Tables contain entity sets.
Q5 - A primary key...
must never have the value NULL.
Unit 2
Q1 - The SQL command SELECT...
reads data from a database, but does not change its contents.
Q2 - The command SELECT X,Y FROM Address...
outputs a virtual table with 2 columns.
Q3 - The ORDER BY element in the SQL command SELECT...
enables a clearer output of the result table.
, Q4 - The GROUP BY element in the SQL command SELECT...
can be used when evaluations of groups of data records are required.
Q5 - Which of the following statements about the SQL command SELECT X,V FROM Y WHERE Z>2
GROUP BY V HAVING COUNT()<3 is correct?
This command cannot be executed because it contains a syntax error.
Unit 3
Q1 - The graphical representation of E/R diagrams...
can be done with UML notation. In this case, the UML class diagram is used.
Q2 - Which of the following statements is correct regarding the following relationship: “A vendor
delivers at least one article and each article is delivered by no or exactly one vendor”?
It is a relationship that cannot be represented by Chen notation.
Q3 - Which of the following statements is correct regarding the following relationship: “A band
gives at least one concert and at each concert at least one band plays”?
This is an N:M relationship.
Q4 - The first normal form for tables in relational databases...
is the basis for the transition to a higher normal form.
Q5 - The second normal form for tables in relational databases...
requires, among other things, the fulfilment of all conditions required for the 1st normal form.
Unit 4
Q1 - Which of the following statements on the logical design of relational databases is correct?
Normalization often leads to several additional foreign key relationships for which consistency
conditions must be created.
