Therefore, it is important that every single record in a database has something to uniquely identify it and this is called the 'Primary Key' or sometimes the 'Key Field'. When you started school, you were given a 'student ID' or an 'office number' (primary key).
Ignoring any maintenance costs, asphalt is generally much cheaper to install than concrete. On average, the cost per square foot for asphalt will run between $2.50 to $4.00. Fluctuations in crude oil prices can cause fluctuations in asphalt prices but the price will remain around this range. Concrete, on the other hand, can run between $4.00 to $6.00 per square foot for basic installation and can cost more depending on different finishes and detail. Itâs not unheard of to have a stained concrete driveway with a smooth finish cost over $15.00 per square foot.
Poured Concrete. According to the Concrete Network, the majority of the cost of a concrete foundation is the concrete itself. The price of concrete varies by region, but as of 2008, it averaged around $75 per cubic yard, or just under $3 per cubic foot.Concrete also requires forms and finishing work at between $1 and $1.50 per square foot and reinforcement with rebar or mesh at a cost of about $.10 per square foot.he price of concrete varies by region, but as of 2008, it averaged around $75 per cubic yard, or just under $3 per cubic foot. Concrete also requires forms and finishing work at between $1 and $1.50 per square foot and reinforcement with rebar or mesh at a cost of about $.10 per square foot.