Database Primary Key: A primary key is a combination of one or more column values in a table that make a row of data unique within a database table. Identification of primary keys is an important part of entity type identification. Ideally, primary keys should be. stable and.
It depends on their experience, the industry of their clients, what their special â¦ ty is, their location, etc., etc.According to the U.S. Department of Labor, the 2002 median annual earnings of salaried computer programmers was $60,290.
The median salary of a computer hardware engineer is more than $98,000 a year. The median salary is the salary at which 50% of the workers earned more and 50% earned less. The lowest 10% of engineers earn less than $62,000 a year, and the highest 10% earn more than $147,000 a year. Computer hardware engineers typically work 40 hours a week. Roughly 25% of engineers work more than this.