htsql / src / htsql / tweak / etl / cmd /

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# Copyright (c) 2006-2012, Prometheus Research, LLC

from ....core.util import listof
from ....core.adapter import Utility, adapt
from ....core.error import BadRequestError
from ....core.entity import TableEntity, ColumnEntity
from ....core.connect import transaction, scramble
from ....core.cmd.fetch import Product
from ....core.cmd.act import Act, ProduceAction, produce
from import VoidBinding
from import decorate
from .command import DeleteCmd
from .insert import BuildExtractNode
from .merge import BuildResolveKey
from import serialize_delete
import itertools

class ExecuteDeletePipe(object):

    def __init__(self, table, key_columns, sql):
        assert isinstance(table, TableEntity)
        assert isinstance(key_columns, listof(ColumnEntity))
        assert isinstance(sql, unicode)
        self.table = table
        self.key_columns = key_columns
        self.sql = sql
        self.key_converts = [scramble(column.domain)
                             for column in key_columns]

    def __call__(self, key_row):
        key_row = tuple(convert(item)
                        for item, convert in zip(key_row, self.key_converts))
        with transaction() as connection:
            cursor = connection.cursor()
            cursor.execute(self.sql.encode('utf-8'), key_row)

class BuildExecuteDelete(Utility):

    def __init__(self, table):
        assert isinstance(table, TableEntity)
        self.table = table

    def __call__(self):
        table = self.table
        key_columns = []
        if table.primary_key is not None:
            key_columns = table.primary_key.origin_columns
            for key in table.unique_keys:
                if key.is_partial:
                if all(not column.is_nullable
                       for column in key.origin_columns):
                    key_columns = key.origin_columns
        if not key_columns:
            raise BadRequestError("table does not have a primary key")
        sql = serialize_delete(table, key_columns)
        return ExecuteDeletePipe(table, key_columns, sql)

class ProduceDelete(Act):

    adapt(DeleteCmd, ProduceAction)

    def __call__(self):
        with transaction() as connection:
            product = produce(self.command.feed)
            extract_node = BuildExtractNode.__invoke__(product.meta,
                    with_id=True, with_fields=False)
            resolve_key = BuildResolveKey.__invoke__(
            execute_delete = BuildExecuteDelete.__invoke__(
            meta = decorate(VoidBinding())
            data = None
            if extract_node.is_list:
                records =
                records = []
            for record in records:
                if record is None:
                id_value, row = extract_node(record)
                key = resolve_key(id_value)
                if key is None:
                    raise BadRequestError("missing record")
            return Product(meta, data)