SQL Language elements
SQL Language elementsThe SQL language is subdivided into several language elements, including:
- Clauses, which are constituent components of statements and queries.
- Expressions, which can produce either scalar values, or tables consisting of columns and rows of data
- Predicates, which specify conditions that can be evaluated to SQL three-valued logic(true/false/unknown) or Boolean truth values and are used to limit the effects of statements and queries, or to change program flow.
- Queries, which retrieve the data based on specific criteria
- Statements, which may have a persistent effect on schemata and data, or may control transactions, program flow, connections, sessions, or diagnostics.
- Insignificant whitespace is generally ignored in SQL statements and queries