Consider the following tables PATIENT and TEST and answer the questions that follow :
Consider the following tables PATIENT and TEST and answer the questions that follow :
Table: PATIENT
| PCODE | NAME | PHONE | DTADMIT | TESTID |
| 6473 | Amit Sharma | 912355899 | 15-JUN-2017 | T102 |
| 7134 | Rose Mathew | 886744536 | 12-NOV-2017 | T101 |
| 8786 | Tina Sharma Arora | 889088765 | 06-DEC-2017 | T102 |
| 6477 | Vijay Shah | 714567445 | 07-DEC-2017 | T502 |
| 7658 | Venkat Fazal | 865545343 | 37-DEC-2017 | T101 |
Note: NAME holds the Names of patients.
DTADMIT holds Dates on which a patient was admitted to hospital.
TESTID holds Ids of Medical tests done on patients.
Table: TEST
| TESTID | TESTNAME | COST |
| T101 | Platelet Count | 200.00 |
| T102 | Hemogram | 190.00 |
| T301 | Malaria Detection | 350.00 |
| T502 | Glucose Test | 150.00 |
Name the Primary keys in both the tables and foreign key in 'PATIENT' table.
3 Answers
PCODE is the primary key in PATIENT table and TESTID is the primary key in TEST table. because primary key of a relational table uniquely identifies each record in the table.
TESTID is the foreign key in PATIENT table whose value is derived from the primary key of test table.
Primary key (Table : PATIENT ) - PCODE as it is unique to each row of table
Primary key (Table : TEST ) – TESTID as it is unique to each row of table
Foreign key in table PATIENT : TESTID as it links the two tables and is Primary key in table TEST
Primary key in PATIENT and TEST tables are PCODE and TESTID respectively. Because primary key of a relational table uniquely identifies each record.
Foreign key in PATIENT table is TESTID whose value is derived from the primary key (TESTID) of another table (TEST).