void FunctionHasColumnInTable::executeImpl(Block & block, const ColumnNumbers & arguments, size_t result, size_t input_rows_count)
{
auto get_string_from_block = [&](size_t column_pos) -> String
{
ColumnPtr column = block.getByPosition(column_pos).column;
const ColumnConst * const_column = checkAndGetColumnConst<ColumnString>(column.get());
return const_column->getValue<String>();
};
size_t arg = 0;
String host_name;
String user_name;
String password;
if (arguments.size() > 3)
host_name = get_string_from_block(arguments[arg++]);
if (arguments.size() > 4)
user_name = get_string_from_block(arguments[arg++]);
if (arguments.size() > 5)
password = get_string_from_block(arguments[arg++]);
String database_name = get_string_from_block(arguments[arg++]);
String table_name = get_string_from_block(arguments[arg++]);
String column_name = get_string_from_block(arguments[arg++]);
bool has_column;
if (host_name.empty())
{
const StoragePtr & table = global_context.getTable(database_name, table_name);
has_column = table->hasColumn(column_name);
}
else
{
std::vector<std::vector<String>> host_names = {{ host_name }};
auto cluster = std::make_shared<Cluster>(
global_context.getSettings(),
host_names,
!user_name.empty() ? user_name : "default",
password,
global_context.getTCPPort(),
false);
auto remote_columns = getStructureOfRemoteTable(*cluster, database_name, table_name, global_context);
has_column = remote_columns.hasPhysical(column_name);
}
block.getByPosition(result).column = DataTypeUInt8().createColumnConst(input_rows_count, has_column);
}
void FunctionIsNull::executeImpl(Block & block, const ColumnNumbers & arguments, size_t result)
{
const ColumnWithTypeAndName & elem = block.getByPosition(arguments[0]);
if (elem.column->isColumnNullable())
{
/// Merely return the embedded null map.
block.getByPosition(result).column = static_cast<const ColumnNullable &>(*elem.column).getNullMapColumnPtr();
}
else
{
/// Since no element is nullable, return a zero-constant column representing
/// a zero-filled null map.
block.getByPosition(result).column = DataTypeUInt8().createColumnConst(elem.column->size(), UInt64(0));
}
}
void DataTypeNullable::deserializeBinaryBulkWithMultipleStreams(
IColumn & column,
size_t limit,
DeserializeBinaryBulkSettings & settings,
DeserializeBinaryBulkStatePtr & state) const
{
ColumnNullable & col = static_cast<ColumnNullable &>(column);
settings.path.push_back(Substream::NullMap);
if (auto stream = settings.getter(settings.path))
DataTypeUInt8().deserializeBinaryBulk(col.getNullMapColumn(), *stream, limit, 0);
settings.path.back() = Substream::NullableElements;
nested_data_type->deserializeBinaryBulkWithMultipleStreams(col.getNestedColumn(), limit, settings, state);
settings.path.pop_back();
}
void DataTypeNullable::serializeBinaryBulkWithMultipleStreams(
const IColumn & column,
size_t offset,
size_t limit,
SerializeBinaryBulkSettings & settings,
SerializeBinaryBulkStatePtr & state) const
{
const ColumnNullable & col = static_cast<const ColumnNullable &>(column);
col.checkConsistency();
/// First serialize null map.
settings.path.push_back(Substream::NullMap);
if (auto stream = settings.getter(settings.path))
DataTypeUInt8().serializeBinaryBulk(col.getNullMapColumn(), *stream, offset, limit);
/// Then serialize contents of arrays.
settings.path.back() = Substream::NullableElements;
nested_data_type->serializeBinaryBulkWithMultipleStreams(col.getNestedColumn(), offset, limit, settings, state);
settings.path.pop_back();
}
