Deprecate unsupported dialects and dbapi

- Deprecate dialects firebird and sybase.

- Deprecate DBAPI

  - mxODBC for mssql

  - oursql for mysql

  - pygresql and py-postgresql for postgresql

- Removed adodbapi DBAPI for mssql

Fixes: #5189
Change-Id: Id9025f4f4de7e97d65aacd0eb4b0c21beb9a67b5

3 files changed, 15 insertions, 2 deletions

diff --git a/lib/sqlalchemy/dialects/sybase/base.py b/lib/sqlalchemy/dialects/sybase/base.py
index 3920aff05..634cf0da4 100644
--- a/lib/sqlalchemy/dialects/sybase/base.py
+++ b/lib/sqlalchemy/dialects/sybase/base.py
@@ -20,6 +20,9 @@
     dialect is not tested within continuous integration and is likely to have
     many issues and caveats not currently handled.
 
+.. deprecated:: 1.4 The Sybase dialect is deprecated and will be removed
+   in a future version.
+
 """
 
 import re
@@ -648,6 +651,14 @@ class SybaseDialect(default.DefaultDialect):
 
     construct_arguments = []
 
+    def __init__(self, *args, **kwargs):
+        util.warn_deprecated(
+            "The Sybase dialect is deprecated and will be removed "
+            "in a future version.",
+            version="1.4",
+        )
+        super(SybaseDialect, self).__init__(*args, **kwargs)
+
     def _get_default_schema_name(self, connection):
         return connection.scalar(
             text("SELECT user_name() as user_name").columns(username=Unicode)
diff --git a/lib/sqlalchemy/dialects/sybase/mxodbc.py b/lib/sqlalchemy/dialects/sybase/mxodbc.py
index 12dcc2cf7..d23482357 100644
--- a/lib/sqlalchemy/dialects/sybase/mxodbc.py
+++ b/lib/sqlalchemy/dialects/sybase/mxodbc.py
@@ -16,7 +16,6 @@
 
     This dialect is a stub only and is likely non functional at this time.
 
-
 """
 from sqlalchemy.connectors.mxodbc import MxODBCConnector
 from sqlalchemy.dialects.sybase.base import SybaseDialect
diff --git a/lib/sqlalchemy/dialects/sybase/pyodbc.py b/lib/sqlalchemy/dialects/sybase/pyodbc.py
index ff166feb1..d11aae1c5 100644
--- a/lib/sqlalchemy/dialects/sybase/pyodbc.py
+++ b/lib/sqlalchemy/dialects/sybase/pyodbc.py
@@ -12,7 +12,6 @@
     :connectstring: sybase+pyodbc://<username>:<password>@<dsnname>[/<database>]
     :url: http://pypi.python.org/pypi/pyodbc/
 
-
 Unicode Support
 ---------------
 
@@ -81,5 +80,9 @@ class SybaseDialect_pyodbc(PyODBCConnector, SybaseDialect):
 
     colspecs = {sqltypes.Numeric: _SybNumeric_pyodbc}
 
+    @classmethod
+    def dbapi(cls):
+        return PyODBCConnector.dbapi()
+
 
 dialect = SybaseDialect_pyodbc