Question

Question # 10
Revis
In a Salesperson table following are non null columns Which column can be selected as pnmary
key​

Answer 1

Answer:

table typically has a column or combination of columns that contain values that uniquely identify each row in the table. This column, or columns, is called the primary key (PK) of the table and enforces the entity integrity of the table. Because primary key constraints guarantee unique data, they are frequently defined on an identity column.

When you specify a primary key constraint for a table, the Database Engine enforces data uniqueness by automatically creating a unique index for the primary key columns. This index also permits fast access to data when the primary key is used in queries. If a primary key constraint is defined on more than one column, values may be duplicated within one column, but each combination of values from all the columns in the primary key constraint definition must be unique.

As shown in the following illustration, the ProductID and VendorID columns in the Purchasing.ProductVendor table form a composite primary key constraint for this table. This makes sure that every row in the ProductVendor table has a unique combination of ProductID and VendorID. This prevents the insertion of duplicate rows.

Answer 2

Answer:

The SalePerson_ID will be the primary key.

Explanation:

• The primary key in the table used to store the unique data.
• It prevents the data redundancy in the database.
• It helps the user to search the unique data quickly with the help of that primary key.
• This can be combination of either only integer values or bot integer and the sting values.

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