Some of the unit-tests have parameters which don't refer to column
names so this is the latest formulation:
if identity_column in [t.c[key].name for key in
self.compiled_parameters[0] if hasattr(t.c, key)]:
On Mar 4, 5:34 pm, "phrrn...@googlemail.com" <phrrn...@googlemail.com>
wrote:
> It is common (for us) to have tables with an identity column and that
> column *not* be the primary key. I am dealing with this by querying
> the system catalogs and caching the result within the table meta-data
> object itself (probably a bad idea but doing it for expediency). The
> system catalog query returns -- of course -- the database-level
> identifier for the column with the identity property set. How do I
> find out if the insert parameters have a value for the identity
> column? I am using something like this which has a very evil look to
> it:
>
> if identity_column in [t.c[key].name for key in
> self.compiled_parameters[0]]:
>
> pjjH
>
> if self.compiled.isinsert:
> self.logger.debug('pre_exec for an
> INSERT')
> t = self.compiled.statement.table
> if self._table_identity_column(t) is not None:
> self.HAS_IDENTITY = True
> # This returns the database-level name of the column
> # Since the parameters may have different names (this
> # will happen if a named parameter, 'key', was passed
> # to the Column constructor), we need to project out
> the names
> identity_column = self._table_identity_column(t)
> self.logger.debug([t.c[key].name for key in
> self.compiled_parameters[0]])
> if identity_column in [t.c[key].name for key in
> self.compiled_parameters[0]]:
> self.IDENTITY_INSERT = True
> self.logger.debug('setting IDENTITY_INSERT ON FOR
> %s' % (t))
>
> # detect if the table has an identity column by direct query against
> the system catalogs
> def _table_identity_column(self, t):
> """Return the name of the this table's identity column"""
> # negative caching
>
> if not hasattr(t, '_identity_column'):
> t._identity_column = None
> s = sql.select([syscolumns.c.name],
> from_obj=syscolumns.join(sysobjects))
> s = s.where(sql.and_(sysobjects.c.name == t.name, sql.text
> ("(status & 128 = 128)")))
> r = self.connection.execute(s).fetchone()
> if r is not None:
> t._identity_column = r[0]
>
return t._identity_column
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