Databases contain data in the form of records within tables and a number of relationships between them.
But there has to be a method of setting up a database in the first place and also a method of accessing the data according to some criteria.
This is why SQL was developed.
SQL stands for Structured Query Language.
SQL is now maintained as a standard language by the American National Standards Institute (or ANSI).
A relational database management system (RDBMS) supports SQL as a control language.
Some RDBMS may have some custom SQL extensions peculiar to itself but it will support all the standard functionality that ANSI compliant SQL offers.
There are many commercial RDBMS such as Oracle and DB2 and there are free open source RDBMS available such as MySQL.
This mini-web will take you through some of the basic commands of SQL
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