SQL Language Elements

by Vickram H 2012-07-30 10:52:17

SQL Language Elements

The SQL language is sub-divided into several
language elements, including:
Clauses, which are in some cases optional, constituent components of statements and queries.
Expressionswhich can produce either scalar values or tables consisting of columns and rows of data.
Predicateswhich specify conditions that can be evaluated to SQL three-valued logic (3VL) Boolean truth values and which are used to limit the effects of statements and queries, or to change program flow.
Queries which retrieve data based on specific criteria.
Statements which may have a persistent effect on schemas and data, or which may control transactions, program flow, connections, sessions, or diagnostics.
• SQL statements also include the semicolon (";") statement terminator. Though not required on every platform, it is defined as a standard part of the SQL grammar.
• Insignificant whitespace is generally ignored in SQL statements and queries, making it easier to format SQL code for readability.

Tagged in:


You must LOGIN to add comments