Support older versions of Sybase via TDS version 4.2 (#25)

* Bumping pymssql version to examine driver issue

* Trying TDS 4.2 if there is a connection error. This feature is for older versions of Sybase.

* Setting TDS version as a string.

* Bumping Version

CHANGELOG.md

@@ -1,4 +1,6 @@
 # Changelog
+## 1.1.0
+* Downgrading FreeTDS version if connection fails for older versions of Sybase.
 ## 1.0.13
 * Using correct format sybase time datatype
   - https://github.com/s7clarke10/tap-sybase/pull/28

setup.py

@@ -4,7 +4,7 @@
 
 setup(
     name="tap-sybase",
-    version="1.0.13",
+    version="1.1.0",
     description="Singer.io tap for extracting data from SQL Server - PipelineWise compatible",
     author="Stitch",
     url="https://github.com/s7clarke10/tap-sybase",
@@ -17,8 +17,7 @@
         "attrs>=24.2.0",
         "pendulum>=1.2.0",
         "realit-singer-python>=5.0.0",
-#        pymssql==2.2.8 broken: https://github.com/pymssql/pymssql/issues/833
-        "pymssql>=2.1.4,!=2.2.8",
+        "pymssql>=2.2.9",
         "backoff>=1.8.0",
     ],
     entry_points="""

tap_sybase/connection.py

@@ -3,6 +3,7 @@
 import backoff
 
 import pymssql
+from   pymssql._mssql import MSSQLDatabaseException
 
 import singer
 import ssl
@@ -39,8 +40,16 @@ def __init__(self, config):
             "tds_version": config.get("tds_version", None),
             "conn_properties": '',
         }
-        conn = pymssql._mssql.connect(**args)
-        super().__init__(conn, False, True)
+
+        try:
+            conn = pymssql._mssql.connect(**args)
+            super().__init__(conn, False, True)
+        except:
+            # Set TDS version to lower version supporting older versions of Sybase
+            # Older versions of Sybase to not support certain keywords like AS
+            args["tds_version"] = "4.2"
+            conn = pymssql._mssql.connect(**args)
+            super().__init__(conn, False, True)
 
     def __enter__(self):
         return self