CHAPTER 7: RELATIONAL DATABASE DESIGN BY ER- AND EER-TO-RELATIONAL MAPPING
Answers to Selected Exercises
7.3 Try to map the relational schema of Figure 6.12 into an ER schema. This is part of
a process known as reverse engineering, where a conceptual schema is created for
an existing implemented database. State any assumptions you make.
Note: We represented BOOK_AUTHORS as a multi-valued attribute of BOOK in the above
ER diagram. Alternatively, it can be represented as a weak entity type.
7.4 Figure 7.7 shows an ER schema for a database that may be used to keep track of
transport ships and their locations for maritime authorities. Map this schema into
a relational schema, and specify all primary keys and foreign keys.
SNAME OWNER TYPE PNAME
SSNAME DATE TIME LONGITUDE LATITUTE
S_C_NAME PNAME S_O_L_NAME
VSNAME VPNAME STARTDATE ENDDATE
f.k. f.k. f.k.
7.5 Map the BANK ER schema of Exercise 3.23 (shown in Figure 3.17) into a
relational schema. Specify all primary keys and foreign keys. Repeat for the AIRLINE schema (Figure 3.16) of Exercise 3.19 and for the other schemas for Exercises 3.16 through 3.24.
CODE NAME ADDR
ACCTNO BALANCE TYPE BCODE BNO
SSN NAME PHONE ADDR
LOANNO AMOUNT TYPE BCODE BNO
BCODE BRANCHNO ADDR