pre_sql_sub_expr

terms

<p>named list of extra info with a name slot containing a single string without spaces.</p>

info

<p>represents an expression.  Unnamed list of pre_sql_terms and character.</p>

A piped query generator based on Edgar F. Codd's relational
algebra, and on production experience using 'SQL' and 'dplyr' at big data
scale.  The design represents an attempt to make 'SQL' more teachable by
denoting composition by a sequential pipeline notation instead of nested
queries or functions.   The implementation delivers reliable high
performance data processing on large data systems such as 'Spark',
databases, and 'data.table'. Package features include: data processing trees
or pipelines as observable objects (able to report both columns
produced and columns used), optimized 'SQL' generation as an explicit
user visible table modeling step, plus explicit query reasoning and checking.

pre_sql_sub_expr: pre_sql_sub_expr

Description

Usage

Arguments

Value