Query Languages

Prime objective of this lecture is to analysis Query Languages. Query languages are computer languages used to make queries directly into databases and data systems. The difference is that a database query language attempts to offer factual answers for you to factual questions, while an data retrieval query language attempts to get documents containing information that may be relevant to a region of inquiry. Query Languages contains: data definition language to define databases and data manipulation language to manipulate databases. SQL provides: Online and embedded use, Dynamic database definition and alteration, Authorization mechanism, Precompilation of embedded queries, Maintenance of indexes and Automatic concurrency control.