diff options
Diffstat (limited to 'lib/sqlalchemy/engine/default.py')
| -rw-r--r-- | lib/sqlalchemy/engine/default.py | 67 |
1 files changed, 53 insertions, 14 deletions
diff --git a/lib/sqlalchemy/engine/default.py b/lib/sqlalchemy/engine/default.py index e062abce6..12ab605e4 100644 --- a/lib/sqlalchemy/engine/default.py +++ b/lib/sqlalchemy/engine/default.py @@ -28,7 +28,6 @@ class DefaultDialect(base.Dialect): ddl_compiler = compiler.DDLCompiler type_compiler = compiler.GenericTypeCompiler preparer = compiler.IdentifierPreparer - defaultrunner = base.DefaultRunner supports_alter = True supports_sequences = False @@ -198,10 +197,7 @@ class DefaultExecutionContext(base.ExecutionContext): self.result_map = None self.cursor = self.create_cursor() self.compiled_parameters = [] - if self.dialect.positional: - self.parameters = [()] - else: - self.parameters = [{}] + self.parameters = [self._default_params] elif compiled_sql is not None: self.compiled = compiled = compiled_sql @@ -273,6 +269,27 @@ class DefaultExecutionContext(base.ExecutionContext): bool(self.compiled.returning) and \ not self.compiled.statement._returning + @util.memoized_property + def _default_params(self): + if self.dialect.positional: + return () + else: + return {} + + def _execute_scalar(self, stmt): + """Execute a string statement on the current cursor, returning a scalar result. + + Used to fire off sequences, default phrases, and "select lastrowid" types of statements individually + or in the context of a parent INSERT or UPDATE statement. + + """ + + conn = self._connection + if isinstance(stmt, unicode) and not self.dialect.supports_unicode_statements: + stmt = stmt.encode(self.dialect.encoding) + conn._cursor_execute(self.cursor, stmt, self._default_params) + return self.cursor.fetchone()[0] + @property def connection(self): return self._connection._branch() @@ -286,10 +303,8 @@ class DefaultExecutionContext(base.ExecutionContext): if self.dialect.positional or self.dialect.supports_unicode_statements: if params: return params - elif self.dialect.positional: - return [()] else: - return [{}] + return [self._default_params] else: def proc(d): # sigh, sometimes we get positional arguments with a dialect @@ -460,6 +475,32 @@ class DefaultExecutionContext(base.ExecutionContext): self._connection._handle_dbapi_exception(e, None, None, None, self) raise + def _exec_default(self, default): + if default.is_sequence: + return self.fire_sequence(default) + elif default.is_callable: + return default.arg(self) + elif default.is_clause_element: + # TODO: expensive branching here should be + # pulled into _exec_scalar() + conn = self.connection + c = expression.select([default.arg]).compile(bind=conn) + return conn._execute_compiled(c, (), {}).scalar() + else: + return default.arg + + def get_insert_default(self, column): + if column.default is None: + return None + else: + return self._exec_default(column.default) + + def get_update_default(self, column): + if column.onupdate is None: + return None + else: + return self._exec_default(column.onupdate) + def __process_defaults(self): """Generate default values for compiled insert/update statements, and generate inserted_primary_key collection. @@ -467,28 +508,26 @@ class DefaultExecutionContext(base.ExecutionContext): if self.executemany: if len(self.compiled.prefetch): - drunner = self.dialect.defaultrunner(self) params = self.compiled_parameters for param in params: self.current_parameters = param for c in self.compiled.prefetch: if self.isinsert: - val = drunner.get_column_default(c) + val = self.get_insert_default(c) else: - val = drunner.get_column_onupdate(c) + val = self.get_update_default(c) if val is not None: param[c.key] = val del self.current_parameters else: self.current_parameters = compiled_parameters = self.compiled_parameters[0] - drunner = self.dialect.defaultrunner(self) for c in self.compiled.prefetch: if self.isinsert: - val = drunner.get_column_default(c) + val = self.get_insert_default(c) else: - val = drunner.get_column_onupdate(c) + val = self.get_update_default(c) if val is not None: compiled_parameters[c.key] = val |