README

Reason

This library exists as a standalone query builder designed to split every single element of a query to allow packages using the library to convert the query into a more performant query, or supporting functionality not available in the original database layer.

Examples

CQL (Cassandra) does not support CONCAT, so this can be pulled from the original query, the fields gathered and then concatinated in PHP.

When running a sharded database, the query can be rebuilt to execute across multiple nodes with the correct partitioning keys, and then presented back to the user as a single result.

Terms

Base on information found on wikipedia - http://en.wikipedia.org/wiki/SQL

Clauses

Are constituent components of statements and queries.

Expressions

which can produce either scalar values, or tables consisting of columns and rows of data

Predicates

Specify conditions that can be evaluated to SQL three-valued logic (3VL) (true/false/unknown) or Boolean truth values and are used to limit the effects of statements and queries, or to change program flow.

Statements

May have a persistent effect on schemata and data, or may control transactions, program flow, connections, sessions, or diagnostics.

Query Statement

Retrieve data based on specific criteria.

Select Expression

Columns and Functions used to build the returning data