ColumnsDescription InterpreterCreateQuery::setColumns(
ASTCreateQuery & create, const Block & as_select_sample, const StoragePtr & as_storage) const
{
ColumnsDescription res;
if (create.columns)
{
res = getColumnsDescription(*create.columns, context);
}
else if (!create.as_table.empty())
{
res = as_storage->getColumns();
}
else if (create.select)
{
for (size_t i = 0; i < as_select_sample.columns(); ++i)
res.ordinary.emplace_back(as_select_sample.safeGetByPosition(i).name, as_select_sample.safeGetByPosition(i).type);
}
else
throw Exception("Incorrect CREATE query: required list of column descriptions or AS section or SELECT.", ErrorCodes::INCORRECT_QUERY);
/// Even if query has list of columns, canonicalize it (unfold Nested columns).
ASTPtr new_columns = formatColumns(res);
if (create.columns)
create.replace(create.columns, new_columns);
else
create.set(create.columns, new_columns);
/// Check for duplicates
std::set<String> all_columns;
auto check_column_already_exists = [&all_columns](const NameAndTypePair & column_name_and_type)
{
if (!all_columns.emplace(column_name_and_type.name).second)
throw Exception("Column " + backQuoteIfNeed(column_name_and_type.name) + " already exists", ErrorCodes::DUPLICATE_COLUMN);
};
for (const auto & elem : res.ordinary)
check_column_already_exists(elem);
for (const auto & elem : res.materialized)
check_column_already_exists(elem);
for (const auto & elem : res.aliases)
check_column_already_exists(elem);
return res;
}
InterpreterCreateQuery::ColumnsInfo InterpreterCreateQuery::setColumns(
ASTCreateQuery & create, const Block & as_select_sample, const StoragePtr & as_storage) const
{
ColumnsInfo res;
if (create.columns)
{
res = getColumnsInfo(create.columns, context);
}
else if (!create.as_table.empty())
{
res.columns = std::make_shared<NamesAndTypesList>(as_storage->getColumnsListNonMaterialized());
res.materialized_columns = as_storage->materialized_columns;
res.alias_columns = as_storage->alias_columns;
res.column_defaults = as_storage->column_defaults;
}
else if (create.select)
{
res.columns = std::make_shared<NamesAndTypesList>();
for (size_t i = 0; i < as_select_sample.columns(); ++i)
res.columns->push_back(NameAndTypePair(as_select_sample.getByPosition(i).name, as_select_sample.getByPosition(i).type));
}
else
throw Exception("Incorrect CREATE query: required list of column descriptions or AS section or SELECT.", ErrorCodes::INCORRECT_QUERY);
/// Даже если в запросе был список столбцов, на всякий случай приведем его к стандартному виду (развернём Nested).
ASTPtr new_columns = formatColumns(*res.columns, res.materialized_columns, res.alias_columns, res.column_defaults);
if (create.columns)
{
auto it = std::find(create.children.begin(), create.children.end(), create.columns);
if (it != create.children.end())
*it = new_columns;
else
create.children.push_back(new_columns);
}
else
create.children.push_back(new_columns);
create.columns = new_columns;
return res;
}
