module documentation

Note

The Firebird dialect within SQLAlchemy is not currently supported. It is not tested within continuous integration and is likely to have many issues and caveats not currently handled. Consider using the external dialect instead.

Deprecated since version 1.4: The internal Firebird dialect is deprecated and will be removed in a future version. Use the external dialect.

Firebird Dialects

Firebird offers two distinct dialects (not to be confused with a SQLAlchemy Dialect):

dialect 1
This is the old syntax and behaviour, inherited from Interbase pre-6.0.
dialect 3
This is the newer and supported syntax, introduced in Interbase 6.0.

The SQLAlchemy Firebird dialect detects these versions and adjusts its representation of SQL accordingly. However, support for dialect 1 is not well tested and probably has incompatibilities.

Locking Behavior

Firebird locks tables aggressively. For this reason, a DROP TABLE may hang until other transactions are released. SQLAlchemy does its best to release transactions as quickly as possible. The most common cause of hanging transactions is a non-fully consumed result set, i.e.:

result = engine.execute(text("select * from table"))
row = result.fetchone()
return

Where above, the CursorResult has not been fully consumed. The connection will be returned to the pool and the transactional state rolled back once the Python garbage collector reclaims the objects which hold onto the connection, which often occurs asynchronously. The above use case can be alleviated by calling first() on the CursorResult which will fetch the first row and immediately close all remaining cursor/connection resources.

RETURNING support

Firebird 2.0 supports returning a result set from inserts, and 2.1 extends that to deletes and updates. This is generically exposed by the SQLAlchemy returning() method, such as:

# INSERT..RETURNING
result = table.insert().returning(table.c.col1, table.c.col2).\
               values(name='foo')
print(result.fetchall())

# UPDATE..RETURNING
raises = empl.update().returning(empl.c.id, empl.c.salary).\
              where(empl.c.sales>100).\
              values(dict(salary=empl.c.salary * 1.1))
print(raises.fetchall())
Constant RESERVED​_WORDS Undocumented
Variable colspecs Undocumented
Variable ischema​_names Undocumented
Class _​FBDate​Time Undocumented
Class _​String​Type Base for Firebird string types.
Class ​FBCompiler Firebird specific idiosyncrasies
Class ​FBDDLCompiler Firebird syntactic idiosyncrasies
Class ​FBDialect Firebird dialect
Class ​FBExecution​Context No class docstring; 1/1 method documented
Class ​FBIdentifier​Preparer Install Firebird specific reserved words.
Class ​FBType​Compiler Undocumented
RESERVED_WORDS =

Undocumented

Value
set(['active',
     'add',
     'admin',
     'after',
     'all',
     'alter',
     'and',
...
colspecs =

Undocumented

ischema_names =

Undocumented