ClickHouse/dbms/include/DB/Parsers/ParserUseQuery.h

50 lines
1016 B
C++

#pragma once
#include <DB/Parsers/IParserBase.h>
#include <DB/Parsers/ExpressionElementParsers.h>
#include <DB/Parsers/CommonParsers.h>
#include <DB/Parsers/ASTIdentifier.h>
#include <DB/Parsers/ASTUseQuery.h>
namespace DB
{
/** Запрос USE db
*/
class ParserUseQuery : public IParserBase
{
protected:
const char * getName() const { return "USE query"; }
bool parseImpl(Pos & pos, Pos end, ASTPtr & node, Pos & max_parsed_pos, Expected & expected)
{
Pos begin = pos;
ParserWhiteSpaceOrComments ws;
ParserString s_use("USE", true, true);
ParserIdentifier name_p;
ASTPtr database;
ws.ignore(pos, end);
if (!s_use.ignore(pos, end, max_parsed_pos, expected))
return false;
ws.ignore(pos, end);
if (!name_p.parse(pos, end, database, max_parsed_pos, expected))
return false;
ws.ignore(pos, end);
auto query = std::make_shared<ASTUseQuery>(StringRange(begin, pos));
query->database = typeid_cast<ASTIdentifier &>(*database).name;
node = query;
return true;
}
};
}