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.
What Computer Hardware Engineers Do. Computer hardware engineers research, design, develop, and test computer systems and components such as processors, circuit boards, memory devices, networks, and routers.By creating new directions in computer hardware, these engineers create rapid advances in computer technology.34,750. The median annual wage for computer hardware engineers was $100,920 in May 2012. The median wage is the wage at which half the workers in an occupation earned more than that amount and half earned less. The lowest 10 percent earned less than $63,970, and the top 10 percent earned more than $150,130.