SQL is the standard language for querying data inside a relational database management system (RDBMS). It is supported by all of the major database systems, such as Microsoft Access, SQL Server, MySQL, Oracle, PostgreSQL, DB2, etc.
SQL is a relatively easy language to learn when compared to most programming languages. It is based on SQL “statements” that, at times, can resemble natural language.
For example:
SELECT CustomerName FROM Customers WHERE CustomerId = 1
The above SQL statement is asking the database to:
“Select the value of the CustomerName column from the Customers table where the CustomerId column’s value equals 1“.