"Ambiguous" numerics with no decimal place
are coerced to int at the connection handler
level. The advantage here is that ints
come back as ints without SQLA type
objects being involved and without needless
conversion to Decimal first.
Unfortunately, some exotic subquery cases
can even see different types between
individual result rows, so the Numeric
handler, when instructed to return Decimal,
can't take full advantage of "native decimal"
mode and must run isinstance() on every value
to check if its Decimal already. Reopen of
[ticket:1840]
range of (8, ), (9, ), (10, ), a warning is emitted
which suggests checking that the FreeTDS version
configuration is using 7.0 or 8.0, not 4.2.
[ticket:1825]
ambiguous typing information about numerics
when columns are embedded in subqueries as well
as when ROWNUM is consulted with subqueries, as we
do for limit/offset. We've added these ambiguous
conditions to the cx_oracle "convert to Decimal()"
handler, so that we receive numerics as Decimal
in more cases instead of as floats. These are
then converted, if requested, into Integer
or Float, or otherwise kept as the lossless
Decimal [ticket:1840].
is passed through render_literal_value(), which may
implement escaping of backslashes. [ticket:1400]
- Postgresql render_literal_value() is overridden which escapes
backslashes, currently applies to the ESCAPE clause
of LIKE and similar expressions.
Ultimately this will have to detect the value of
"standard_conforming_strings" for full behavior.
[ticket:1400]
- MySQL render_literal_value() is overridden which escapes
backslashes, currently applies to the ESCAPE clause
of LIKE and similar expressions. This behavior
is derived from detecting the value of
NO_BACKSLASH_ESCAPES. [ticket:1400]
constraint gets moved to column level due to SQLite
AUTOINCREMENT keyword being rendered. [ticket:1812]
- remove some extra space in between constraint DDL
- added alias() to binary comparison test, fixing pg + mysql failures
including that use_ansi is set to False automatically,
NVARCHAR2 and NCLOB are not rendered for Unicode,
"native unicode" check doesn't fail, cx_oracle
"native unicode" mode is disabled, VARCHAR() is emitted
with bytes count instead of char count. [ticket:1808]
when limit/offset is used, i.e. the ROWNUM subquery.
However, Oracle can't really handle FOR UPDATE with ORDER BY
or with subqueries, so its still not very usable, but at
least SQLA gets the SQL past the Oracle parser.
[ticket:1815]
and also that FB's cursor.rowcount is a little expensive, but not dramatically.
added a test to ensure cursor.rowcount is only called on update/delete.
the current default for firebird enable_rowcount is now True, leaving all the
options to turn it off etc..
by default, and can be re-enabled using the 'enable_rowcount'
flag with create_engine(), as well as the 'enable_rowcount'
execution context flag on a per-execute basis. This because
cursor.rowcount requires cursor access (can't be evaluated
lazily since the result auto-closes) and also incurs an
expensive round-trip.
unknown numeric is received.
- psycopg2/pg8000 dialects now aware of REAL[], FLOAT[],
DOUBLE_PRECISION[], NUMERIC[] return types without
raising an exception.
- introducing testing.provide_metadata for all these stupid little
create/drop tests
DBAPI returns natively the kinds of values we prefer:
- NUMBER values with positive precision + scale convert
to cx_oracle.STRING and then to Decimal. This
allows perfect precision for the Numeric type when
using cx_oracle. [ticket:1759]
- STRING/FIXED_CHAR now convert to unicode natively.
SQLAlchemy's String types then don't need to
apply any kind of conversions.
postgresql dialect directly, which add the PG-specific
argument 'precision' to both. 'precision' and
'timezone' are correctly reflected for both TIME and
TIMEZONE types. [ticket:997]
using character counts, i.e. VARCHAR2(50 CHAR), so that
the column is sized in terms of characters and not bytes.
Column reflection of character types will also use
ALL_TAB_COLUMNS.CHAR_LENGTH instead of
ALL_TAB_COLUMNS.DATA_LENGTH. Both of these behaviors take
effect when the server version is 9 or higher - for
version 8, the old behaviors are used. [ticket:1744]
relationship(), to eliminate confusion over the relational
algebra term. relation() however will remain available
in equal capacity for the foreseeable future. [ticket:1740]
- modified SQLCompiler to support rendering of bind parameters as literal
inline strings for specific sections, if specified by the compiler
subclass, using either literal_binds=True passed to process() or any visit
method, or by setting to False the "binds_in_columns_clause" flag for SQL-92
compatible columns clauses.. The compiler subclass is responsible for
implementing the literal quoting function which should make use of the DBAPI's native
capabilities.
- SQLCompiler now passes **kw to most process() methods (should be all,
ideally) so that literal_binds is propagated.
- added some rudimentary tests for mxodbc.
changes to Enum/SchemaType to re-support adaptation of string types.
This approach can be adapted by "conditional" unicode returning dialects
(i.e. pyodbc and possibly mxodbc) to remove the overhead
of isinstance(value, unicode) calls when the dialect returned type is
of dbapi.UNICODE, dbapi.NVARCHAR, etc.
Mike Bayer