def __init__(self, typename, nullable=False):
m = base_typename_re.match(typename)
base_typename = m.groups()[0]
if base_typename not in _clickhouse_dtypes:
raise com.UnsupportedBackendType(typename)
self.typename = base_typename
self.nullable = nullable
def get_schema(self, table_name, database=None):
"""
Return a Schema object for the indicated table and database
Parameters
----------
table_name : string
May be fully qualified
database : string, default None
Returns
-------
schema : ibis Schema
"""
qualified_name = self._fully_qualified_name(table_name, database)
query = 'DESC {0}'.format(qualified_name)
data, _ = self._execute(query)
names, types = data[:2]
ibis_types = clickhouse_types_to_ibis_types(types)
try:
ibis_types = map(clickhouse_to_ibis.__getitem__, types)
except KeyError:
raise com.UnsupportedBackendType()
return sch.Schema(names, ibis_types)
def _type_to_sql_string(tval):
if isinstance(tval, dt.Decimal):
return 'decimal({}, {})'.format(tval.precision, tval.scale)
name = tval.name.lower()
try:
return _sql_type_names[name]
except KeyError:
raise com.UnsupportedBackendType(name)
def bq_param_array(param, value):
param_type = param.type()
assert isinstance(param_type, dt.Array), str(param_type)
try:
bigquery_type = _IBIS_TYPE_TO_DTYPE[str(param_type.value_type)]
except KeyError:
raise com.UnsupportedBackendType(param_type)
else:
return bq.ArrayQueryParameter(param._name, bigquery_type, value)
def clickhouse_types_to_ibis_types(types):
result = []
for t in types:
try:
value = clickhouse_to_ibis[t]
except KeyError:
raise com.UnsupportedBackendType(t)
else:
result.append(value)
return result
def bq_param_array(param, value):
param_type = param.type()
assert isinstance(param_type, dt.Array), str(param_type)
try:
bigquery_type = ibis_type_to_bigquery_type(param_type.value_type)
except NotImplementedError:
raise com.UnsupportedBackendType(param_type)
else:
if isinstance(param_type.value_type, dt.Struct):
query_value = [
bigquery_param(param[i].name('element_{:d}'.format(i)), struct)
for i, struct in enumerate(value)
]
bigquery_type = 'STRUCT'
elif isinstance(param_type.value_type, dt.Array):
raise TypeError('ARRAY<ARRAY<T>> is not supported in BigQuery')
else:
query_value = value
result = bq.ArrayQueryParameter(
param.get_name(), bigquery_type, query_value)
return result
def __init__(self, typename, nullable=True):
if typename not in self.dtypes:
raise com.UnsupportedBackendType(typename)
self.typename = typename
self.nullable = nullable
def __init__(self, typename, nullable=False):
if typename not in _clickhouse_dtypes:
raise com.UnsupportedBackendType(typename)
self.typename = typename
self.nullable = nullable
def _db_type_to_dtype(self, db_type, column):
try:
return clickhouse_to_pandas[db_type]
except KeyError:
return com.UnsupportedBackendType(db_type)
