- The Oracle dialect will issue VARCHAR type definitions

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]

1 files changed, 16 insertions, 5 deletions

diff --git a/lib/sqlalchemy/dialects/oracle/base.py b/lib/sqlalchemy/dialects/oracle/base.py
index 2af5bdd7d..332fa805d 100644
--- a/lib/sqlalchemy/dialects/oracle/base.py
+++ b/lib/sqlalchemy/dialects/oracle/base.py
@@ -286,7 +286,10 @@ class OracleTypeCompiler(compiler.GenericTypeCompiler):
             return "%(name)s(%(precision)s, %(scale)s)" % {'name':name,'precision': precision, 'scale' : scale}
         
     def visit_VARCHAR(self, type_):
-        return "VARCHAR(%(length)s)" % {'length' : type_.length}
+        if self.dialect.supports_char_length:
+            return "VARCHAR(%(length)s CHAR)" % {'length' : type_.length}
+        else:
+            return "VARCHAR(%(length)s)" % {'length' : type_.length}
 
     def visit_NVARCHAR(self, type_):
         return "NVARCHAR2(%(length)s)" % {'length' : type_.length}
@@ -569,7 +572,8 @@ class OracleDialect(default.DefaultDialect):
     execution_ctx_cls = OracleExecutionContext
     
     reflection_options = ('oracle_resolve_synonyms', )
-    
+
+    supports_char_length = True    
     
     def __init__(self, 
                 use_ansi=True, 
@@ -584,6 +588,8 @@ class OracleDialect(default.DefaultDialect):
         self.implicit_returning = self.server_version_info > (10, ) and \
                                         self.__dict__.get('implicit_returning', True)
 
+        self.supports_char_length = self.server_version_info >= (9, )
+
         if self.server_version_info < (9,):
             self.colspecs = self.colspecs.copy()
             self.colspecs.pop(sqltypes.Interval)
@@ -749,11 +755,16 @@ class OracleDialect(default.DefaultDialect):
                                           resolve_synonyms, dblink,
                                           info_cache=info_cache)
         columns = []
+        if self.supports_char_length:
+            char_length_col = 'char_length'
+        else:
+            char_length_col = 'data_length'
+ 
         c = connection.execute(sql.text(
-                "SELECT column_name, data_type, data_length, data_precision, data_scale, "
+                "SELECT column_name, data_type, %(char_length_col)s, data_precision, data_scale, "
                 "nullable, data_default FROM ALL_TAB_COLUMNS%(dblink)s "
                 "WHERE table_name = :table_name AND owner = :owner " 
-                "ORDER BY column_id" % {'dblink': dblink}),
+                "ORDER BY column_id" % {'dblink': dblink, 'char_length_col':char_length_col}),
                                table_name=table_name, owner=schema)
 
         for row in c:
@@ -762,7 +773,7 @@ class OracleDialect(default.DefaultDialect):
 
             if coltype == 'NUMBER' :
                 coltype = NUMBER(precision, scale)
-            elif coltype=='CHAR' or coltype=='VARCHAR2':
+            elif coltype in ('VARCHAR2', 'NVARCHAR2', 'CHAR'):
                 coltype = self.ischema_names.get(coltype)(length)
             elif 'WITH TIME ZONE' in coltype: 
                 coltype = TIMESTAMP(timezone=True)