Added modular DAL, updated gluon imports to new structure

gluon/dal/adapters/teradata.py

@@ -0,0 +1,76 @@
+# -*- coding: utf-8 -*-
+
+from .._globals import IDENTITY
+from ..connection import ConnectionPool
+from .base import BaseAdapter
+
+
+class TeradataAdapter(BaseAdapter):
+    drivers = ('pyodbc',)
+
+    types = {
+        'boolean': 'CHAR(1)',
+        'string': 'VARCHAR(%(length)s)',
+        'text': 'VARCHAR(2000)',
+        'json': 'VARCHAR(4000)',
+        'password': 'VARCHAR(%(length)s)',
+        'blob': 'BLOB',
+        'upload': 'VARCHAR(%(length)s)',
+        'integer': 'INT',
+        'bigint': 'BIGINT',
+        'float': 'REAL',
+        'double': 'DOUBLE',
+        'decimal': 'NUMERIC(%(precision)s,%(scale)s)',
+        'date': 'DATE',
+        'time': 'TIME',
+        'datetime': 'TIMESTAMP',
+        # Modified Constraint syntax for Teradata.
+        # Teradata does not support ON DELETE.
+        'id': 'INT GENERATED ALWAYS AS IDENTITY',  # Teradata Specific
+        'reference': 'INT',
+        'list:integer': 'VARCHAR(4000)',
+        'list:string': 'VARCHAR(4000)',
+        'list:reference': 'VARCHAR(4000)',
+        'big-id': 'BIGINT GENERATED ALWAYS AS IDENTITY',  # Teradata Specific
+        'big-reference': 'BIGINT',
+        'reference FK': ' REFERENCES %(foreign_key)s',
+        'reference TFK': ' FOREIGN KEY (%(field_name)s) REFERENCES %(foreign_table)s (%(foreign_key)s)',
+        }
+
+    def __init__(self,db,uri,pool_size=0,folder=None,db_codec ='UTF-8',
+                 credential_decoder=IDENTITY, driver_args={},
+                 adapter_args={}, do_connect=True, after_connection=None):
+        self.db = db
+        self.dbengine = "teradata"
+        self.uri = uri
+        if do_connect: self.find_driver(adapter_args,uri)
+        self.pool_size = pool_size
+        self.folder = folder
+        self.db_codec = db_codec
+        self._after_connection = after_connection
+        self.find_or_make_work_folder()
+        ruri = uri.split('://', 1)[1]
+        def connector(cnxn=ruri,driver_args=driver_args):
+            return self.driver.connect(cnxn,**driver_args)
+        self.connector = connector
+        if do_connect: self.reconnect()
+
+    def close(self,action='commit',really=True):
+        # Teradata does not implicitly close off the cursor
+        # leading to SQL_ACTIVE_STATEMENTS limit errors
+        self.cursor.close()
+        ConnectionPool.close(self, action, really)
+
+    def LEFT_JOIN(self):
+        return 'LEFT OUTER JOIN'
+
+    # Similar to MSSQL, Teradata can't specify a range (for Pageby)
+    def select_limitby(self, sql_s, sql_f, sql_t, sql_w, sql_o, limitby):
+        if limitby:
+            (lmin, lmax) = limitby
+            sql_s += ' TOP %i' % lmax
+        return 'SELECT %s %s FROM %s%s%s;' % (sql_s, sql_f, sql_t, sql_w, sql_o)
+
+    def _truncate(self, table, mode=''):
+        tablename = table._tablename
+        return ['DELETE FROM %s ALL;' % (tablename)]