Query Languages

1. A query language is a language in which a user requests information from a database. These are typically higher-level than programming languages.

   They may be one of:

   • Procedural, where the user instructs the system to perform a sequence of operations on the database. This will compute the desired information.
   • Nonprocedural, where the user specifies the information desired without giving a procedure for obtaining the information.
2. A complete query language also contains facilities to insert and delete tuples as well as to modify parts of existing tuples.