ClickHouse/src/Interpreters/InterpreterShowCreateQuery.cpp
2021-11-11 11:43:00 +00:00

109 lines
3.8 KiB
C++

#include <Storages/IStorage.h>
#include <Parsers/TablePropertiesQueriesASTs.h>
#include <Parsers/formatAST.h>
#include <Processors/Sources/SourceFromSingleChunk.h>
#include <QueryPipeline/BlockIO.h>
#include <DataTypes/DataTypesNumber.h>
#include <DataTypes/DataTypeString.h>
#include <Columns/ColumnString.h>
#include <Common/typeid_cast.h>
#include <Access/Common/AccessFlags.h>
#include <Interpreters/Context.h>
#include <Interpreters/InterpreterShowCreateQuery.h>
#include <Parsers/ASTCreateQuery.h>
namespace DB
{
namespace ErrorCodes
{
extern const int SYNTAX_ERROR;
extern const int THERE_IS_NO_QUERY;
extern const int BAD_ARGUMENTS;
}
BlockIO InterpreterShowCreateQuery::execute()
{
BlockIO res;
res.pipeline = executeImpl();
return res;
}
Block InterpreterShowCreateQuery::getSampleBlock()
{
return Block{{
ColumnString::create(),
std::make_shared<DataTypeString>(),
"statement"}};
}
QueryPipeline InterpreterShowCreateQuery::executeImpl()
{
ASTPtr create_query;
ASTQueryWithTableAndOutput * show_query;
if ((show_query = query_ptr->as<ASTShowCreateTableQuery>()) ||
(show_query = query_ptr->as<ASTShowCreateViewQuery>()) ||
(show_query = query_ptr->as<ASTShowCreateDictionaryQuery>()))
{
auto resolve_table_type = show_query->temporary ? Context::ResolveExternal : Context::ResolveOrdinary;
auto table_id = getContext()->resolveStorageID(*show_query, resolve_table_type);
bool is_dictionary = static_cast<bool>(query_ptr->as<ASTShowCreateDictionaryQuery>());
if (is_dictionary)
getContext()->checkAccess(AccessType::SHOW_DICTIONARIES, table_id);
else
getContext()->checkAccess(AccessType::SHOW_COLUMNS, table_id);
create_query = DatabaseCatalog::instance().getDatabase(table_id.database_name)->getCreateTableQuery(table_id.table_name, getContext());
auto & ast_create_query = create_query->as<ASTCreateQuery &>();
if (query_ptr->as<ASTShowCreateViewQuery>())
{
if (!ast_create_query.isView())
throw Exception(ErrorCodes::BAD_ARGUMENTS, "{}.{} is not a VIEW",
backQuote(ast_create_query.getDatabase()), backQuote(ast_create_query.getTable()));
}
else if (is_dictionary)
{
if (!ast_create_query.is_dictionary)
throw Exception(ErrorCodes::BAD_ARGUMENTS, "{}.{} is not a DICTIONARY",
backQuote(ast_create_query.getDatabase()), backQuote(ast_create_query.getTable()));
}
}
else if ((show_query = query_ptr->as<ASTShowCreateDatabaseQuery>()))
{
if (show_query->temporary)
throw Exception("Temporary databases are not possible.", ErrorCodes::SYNTAX_ERROR);
show_query->setDatabase(getContext()->resolveDatabase(show_query->getDatabase()));
getContext()->checkAccess(AccessType::SHOW_DATABASES, show_query->getDatabase());
create_query = DatabaseCatalog::instance().getDatabase(show_query->getDatabase())->getCreateDatabaseQuery();
}
if (!create_query)
throw Exception("Unable to show the create query of " + show_query->getTable() + ". Maybe it was created by the system.", ErrorCodes::THERE_IS_NO_QUERY);
if (!getContext()->getSettingsRef().show_table_uuid_in_table_create_query_if_not_nil)
{
auto & create = create_query->as<ASTCreateQuery &>();
create.uuid = UUIDHelpers::Nil;
create.to_inner_uuid = UUIDHelpers::Nil;
}
WriteBufferFromOwnString buf;
formatAST(*create_query, buf, false, false);
String res = buf.str();
MutableColumnPtr column = ColumnString::create();
column->insert(res);
return QueryPipeline(std::make_shared<SourceFromSingleChunk>(Block{{
std::move(column),
std::make_shared<DataTypeString>(),
"statement"}}));
}
}