# -*- coding: utf-8 -*-
from .._globals import IDENTITY
from ..connection import ConnectionPool
from .base import BaseAdapter
[docs]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)',
'geometry': 'ST_GEOMETRY',
'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()
[docs] 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)
[docs] def LEFT_JOIN(self):
return 'LEFT OUTER JOIN'
# Similar to MSSQL, Teradata can't specify a range (for Pageby)
[docs] 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)]