How to prevent duplicate entries in MySQL and PHP?

What is SAS, does it need a third party database to work, or is SAS itself a database?

• If I wanted to develop a tool where people could enter form information into a web based form so that the field data was imported into a SAS system, what SAS products would I need to do this? Also, I would want to check the field data, say for first and last name fields, entered via the form against already the data that already exists in the database to prevent duplicate entries and to only update the existing entry with any new information entered via the webform. This data would then be queriable and reportable across a number of different tools, some for analysis and others for simple data mining. Most importantly, does SAS have its own database or does it require a third party database such as Oracle, SQL, Sybase, mySQL, etc? Can SAS be used to do this? If so please explain, if I'm asking too much you can explain part of it as that would help a lot.

• Answer:

  SAS is Statistics Analytics Software../ From traditional statistical analysis of variance and predictive modeling to exact methods and statistical visualization techniques SAS/STAT software is designed for both specialized and enterprisewide analytical needs. SAS/STAT software provides a complete, comprehensive set of tools that can meet the data analysis needs of the entire organization. Benefits: Take advantage of all data in order to uncover new business opportunities and increase revenue. Move the scientific discovery process forward by applying the latest statistical techniques.