[Sqlalchemy-tickets] Issue #3953: expanding parameter (zzzeek/sqlalchemy)

[Michael B. <iss...@bi...>]

New issue 3953: expanding parameter
https://bitbucket.org/zzzeek/sqlalchemy/issues/3953/expanding-parameter

Michael Bayer:

this is for the purpose of IN() in conjunction with query caching.    Idea is to allow this to be viable with "select in" loading and "select in" inheritance so that these are compatible w/ "baked".

    stmt = select([table]).where(table.c.col.in_(bindparam('foo', expanding=True))
    conn.execute(stmt, {"foo": [1, 2, 3]})

the string statement is converted at ExecutionContext time with an extra search and replace.  this so that all the caching steps can be used against the above query w/ a dynamic list for IN.