August 2009
Intermediate to advanced
893 pages
26h 48m
English
Structured Query Language (SQL), also called Structured English Query Language (SEQUEL), is relational query language. It is the standard command set used to communicate with the relational database management system (RDBMS). It is based on the tuple relational calculus, though not as closely as QUEL. SQL resembles relational algebra in some places and tuple relational calculus in others. It is a non-procedural language in which block structured format of English key words is used. SEQUEL (widely known as SQL) was the first prototype query language developed by IBM in the early-1970s. It was first implemented on a large scale in IBM prototype called System R and subsequently extended to numerous commerical ...