morro

sqlalchemy/dialects/postgresql/pg8000.py

@@ -0,0 +1,105 @@
+"""Support for the PostgreSQL database via the pg8000 driver.
+
+Connecting
+----------
+
+URLs are of the form
+`postgresql+pg8000://user:password@host:port/dbname[?key=value&key=value...]`.
+
+Unicode
+-------
+
+pg8000 requires that the postgresql client encoding be configured in the postgresql.conf file
+in order to use encodings other than ascii.  Set this value to the same value as 
+the "encoding" parameter on create_engine(), usually "utf-8".
+
+Interval
+--------
+
+Passing data from/to the Interval type is not supported as of yet.
+
+"""
+import decimal
+
+from sqlalchemy.engine import default
+from sqlalchemy import util, exc
+from sqlalchemy import processors
+from sqlalchemy import types as sqltypes
+from sqlalchemy.dialects.postgresql.base import PGDialect, \
+                PGCompiler, PGIdentifierPreparer, PGExecutionContext
+
+class _PGNumeric(sqltypes.Numeric):
+    def result_processor(self, dialect, coltype):
+        if self.asdecimal:
+            if coltype in (700, 701):
+                return processors.to_decimal_processor_factory(decimal.Decimal)
+            elif coltype == 1700:
+                # pg8000 returns Decimal natively for 1700
+                return None
+            else:
+                raise exc.InvalidRequestError("Unknown PG numeric type: %d" % coltype)
+        else:
+            if coltype in (700, 701):
+                # pg8000 returns float natively for 701
+                return None
+            elif coltype == 1700:
+                return processors.to_float
+            else:
+                raise exc.InvalidRequestError("Unknown PG numeric type: %d" % coltype)
+
+class PGExecutionContext_pg8000(PGExecutionContext):
+    pass
+
+
+class PGCompiler_pg8000(PGCompiler):
+    def visit_mod(self, binary, **kw):
+        return self.process(binary.left) + " %% " + self.process(binary.right)
+
+    def post_process_text(self, text):
+        if '%%' in text:
+            util.warn("The SQLAlchemy postgresql dialect now automatically escapes '%' in text() "
+                      "expressions to '%%'.")
+        return text.replace('%', '%%')
+
+
+class PGIdentifierPreparer_pg8000(PGIdentifierPreparer):
+    def _escape_identifier(self, value):
+        value = value.replace(self.escape_quote, self.escape_to_quote)
+        return value.replace('%', '%%')
+
+    
+class PGDialect_pg8000(PGDialect):
+    driver = 'pg8000'
+
+    supports_unicode_statements = True
+    
+    supports_unicode_binds = True
+    
+    default_paramstyle = 'format'
+    supports_sane_multi_rowcount = False
+    execution_ctx_cls = PGExecutionContext_pg8000
+    statement_compiler = PGCompiler_pg8000
+    preparer = PGIdentifierPreparer_pg8000
+    
+    colspecs = util.update_copy(
+        PGDialect.colspecs,
+        {
+            sqltypes.Numeric : _PGNumeric,
+        }
+    )
+    
+    @classmethod
+    def dbapi(cls):
+        return __import__('pg8000').dbapi
+
+    def create_connect_args(self, url):
+        opts = url.translate_connect_args(username='user')
+        if 'port' in opts:
+            opts['port'] = int(opts['port'])
+        opts.update(url.query)
+        return ([], opts)
+
+    def is_disconnect(self, e):
+        return "connection is closed" in str(e)
+
+dialect = PGDialect_pg8000