[Sqlalchemy-tickets] Issue #3793: Claim that 'column elements' are the most fundamental part of expression API seems contradictory (zzzeek/sqlalchemy)

[keeyip c. <iss...@bi...>]

New issue 3793: Claim that 'column elements' are the most fundamental part of expression API seems contradictory
https://bitbucket.org/zzzeek/sqlalchemy/issues/3793/claim-that-column-elements-are-the-most

keeyip chan:

I am referring to the first paragraph of 
http://docs.sqlalchemy.org/en/latest/core/sqlelement.html#sqlalchemy.sql.expression.text

I may just be confused by the order of sentences, but it seems that the "most fundamental part" ought to be "clause elements" rather than "column elements". It just seems contradictory to state in one sentence that column elements are the most fundamental but then claim that the "core of all SQL expression constructs is the ClauseElement".

**Proposed rewording:**
The expression API represents each part of a SQL expression as a subclass of ClauseElement. Subclasses are used to represent conjunctions, column selections, filters, and many other types of SQL clauses. The most basic of these clauses is the ColumnElement, which represents a column and its datatype. The expression API defines interfaces for combining ClauseElement objects and to generate SQL statements from those combinations.