what is primary key?in table how many times use primary key?

India
March 28, 2008 1:02am CST
i am learning sql
1 response
kishorebabu4u
@kishorebabu4u (76)
• India
6 Jan 09
A table typically has a column or combination of columns that contain values that uniquely identify each row in the table. This is column or columns, is called the primary key (PK) of the table and enforces the entity integrity of the table. A table can have only one PRIMARY KEY constraint.