ClickHouse/dbms/src/Interpreters/InterpreterShowCreateQuery.cpp

76 lines
2.0 KiB
C++

#include <sstream>
#include <Storages/IStorage.h>
#include <Parsers/TablePropertiesQueriesASTs.h>
#include <Parsers/formatAST.h>
#include <DataStreams/OneBlockInputStream.h>
#include <DataStreams/BlockIO.h>
#include <DataStreams/copyData.h>
#include <DataTypes/DataTypesNumber.h>
#include <DataTypes/DataTypeString.h>
#include <Columns/ColumnString.h>
#include <Common/typeid_cast.h>
#include <Interpreters/Context.h>
#include <Interpreters/InterpreterShowCreateQuery.h>
namespace DB
{
namespace ErrorCodes
{
extern const int SYNTAX_ERROR;
extern const int THERE_IS_NO_QUERY;
}
BlockIO InterpreterShowCreateQuery::execute()
{
BlockIO res;
res.in = executeImpl();
return res;
}
Block InterpreterShowCreateQuery::getSampleBlock()
{
return Block{{
ColumnString::create(),
std::make_shared<DataTypeString>(),
"statement"}};
}
BlockInputStreamPtr InterpreterShowCreateQuery::executeImpl()
{
/// FIXME: try to prettify this cast using `as<>()`
const auto & ast = dynamic_cast<const ASTQueryWithTableAndOutput &>(*query_ptr);
if (ast.temporary && !ast.database.empty())
throw Exception("Temporary databases are not possible.", ErrorCodes::SYNTAX_ERROR);
ASTPtr create_query;
if (ast.temporary)
create_query = context.getCreateExternalTableQuery(ast.table);
else if (ast.table.empty())
create_query = context.getCreateDatabaseQuery(ast.database);
else
create_query = context.getCreateTableQuery(ast.database, ast.table);
if (!create_query && ast.temporary)
throw Exception("Unable to show the create query of " + ast.table + ". Maybe it was created by the system.", ErrorCodes::THERE_IS_NO_QUERY);
std::stringstream stream;
formatAST(*create_query, stream, false, true);
String res = stream.str();
MutableColumnPtr column = ColumnString::create();
column->insert(res);
return std::make_shared<OneBlockInputStream>(Block{{
std::move(column),
std::make_shared<DataTypeString>(),
"statement"}});
}
}