Page 96 - Viva ICSE Computer Studies 7 : E-book

3. Enter the fi eld name for that particular data type.
Step 3

Setting Data Type in Design View

Follow these steps to set data type in Design view
1. Open the table in the ‘Design’ view.
2. Enter the fi eld name. By default, it is assigned the text data type.

3. Click on the drop-down arrow in the ‘Data Type’ column and select the desired data
type.

Think and Discuss
Step 2 Step 3
Name a few properties of a Field
Name displayed in the Field
Properties pane.

Step 1

Primary Key

Primary key is a key in a relational database that is unique for each record. It is a unique identifi er,
such as a driver license number, telephone number or vehicle identifi cation number (VIN).
A relational database must always have one and only one primary key. Primary keys must
contain UNIQUE values and cannot contain NULL values. If we consider employee table, then
for this table ‘emp_id’ can be a primary key as no two employees can have same ID. We cannot
take name as the primary key because people can have same names. The primary key works as
a tool that keeps a check on the table that every record entered is unique.

Setting a Primary Key
Follow these steps to set a
primary key.

1. Click on the Design tab.
2. Click on the Primary Step 1
Key button in the ‘Tools’ Step 2 Step 3
group.

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