Question

In your own words, define the following database terms and give an example of each:

Table

Record

Field

Primary Key

Foreign Key

Answer 1

Table -
A table is a set of data element using the columns and rows.
which store the data.which has a number of columns and rows.
e.g - A table of student which contains student data.

---------+---------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+---------+---------------+------+-----+---------+-------+
| ID | int(11) | NO | PRI | | |
| NAME | varchar(20) | NO | | | |
| AGE | int(11) | NO | | | |
| ADDRESS | char(25) | YES | | NULL | |
| SALARY | decimal(18,2) | YES | | NULL | |
+---------+---------------+------+-----+---------+-------+

Record -

A single entry in a table is called a record or row.
A record in a table represent set of related data.

e.g. example of single record.

1   Adam   34   13000.

Field -

A table consist of several records i.e row ,each record can be brocken
into several smaller entities known as field.

e.g a table consist of four field, ID,NAME,AGE,SALARY.

Primary Key -

Is the a column inside a table which is used to identify each row or record in a table.

e.g. -

CREATE TABLE Persons
(
P_Id int NOT NULL,
LastName varchar(255) NOT NULL,
FirstName varchar(255),
Address varchar(255),
City varchar(255),
PRIMARY KEY (P_Id)
)

P_Id is the primary key inside a table Person.

Foreign Key -

A Foreign key is the key inside the table which points to primary key of another table.

e.g
-

CREATE TABLE customer1(
cust_code char(6) NOT NULL PRIMARY KEY,
cust_name char(25),
cust_city char(25),
agent_code char(6),
FOREIGN KEY(agent_code)
REFERENCES agents (agent_code)
) ;

where agent_code is the foreign key.