Languages and Programming Interfaces
Crucial to the dominance of the relational database was the almost universal adoption of the SQL language as the mechanism for querying and modifying data. SQL is not a perfect language, but it has demonstrated sufficient flexibility to meet the needs of both non-programming database users and professional database programmers. Programmers embed SQL in programming languages, while non-programmers use SQL either explicitly within a query tool or implicitly when a BI tool uses SQL under the hood to talk to the database. Prior to the introduction of SQL, most IT departments labored with a backlog of requests for reports; SQL allowed the business user to “self-serve” these requests.