ClickHouse/dbms/src/Parsers/ParserRenameQuery.cpp
2016-11-20 15:43:20 +03:00

96 lines
2.1 KiB
C++

#include <DB/Parsers/ASTIdentifier.h>
#include <DB/Parsers/ASTRenameQuery.h>
#include <DB/Parsers/CommonParsers.h>
#include <DB/Parsers/ParserRenameQuery.h>
#include <DB/Common/typeid_cast.h>
namespace DB
{
/// Парсит database.table или table.
static bool parseDatabaseAndTable(
ASTRenameQuery::Table & db_and_table, IParser::Pos & pos, IParser::Pos end, IParser::Pos & max_parsed_pos, Expected & expected)
{
ParserIdentifier name_p;
ParserWhiteSpaceOrComments ws;
ParserString s_dot(".");
ASTPtr database;
ASTPtr table;
ws.ignore(pos, end);
if (!name_p.parse(pos, end, table, max_parsed_pos, expected))
return false;
ws.ignore(pos, end);
if (s_dot.ignore(pos, end, max_parsed_pos, expected))
{
database = table;
if (!name_p.parse(pos, end, table, max_parsed_pos, expected))
return false;
ws.ignore(pos, end);
}
db_and_table.database = database ? typeid_cast<const ASTIdentifier &>(*database).name : "";
db_and_table.table = typeid_cast<const ASTIdentifier &>(*table).name;
return true;
}
bool ParserRenameQuery::parseImpl(Pos & pos, Pos end, ASTPtr & node, Pos & max_parsed_pos, Expected & expected)
{
Pos begin = pos;
ParserWhiteSpaceOrComments ws;
ParserString s_rename("RENAME", true, true);
ParserString s_table("TABLE", true, true);
ParserString s_to("TO", true, true);
ParserString s_comma(",");
ws.ignore(pos, end);
if (!s_rename.ignore(pos, end, max_parsed_pos, expected))
return false;
ws.ignore(pos, end);
if (!s_table.ignore(pos, end, max_parsed_pos, expected))
return false;
ASTRenameQuery::Elements elements;
while (true)
{
ws.ignore(pos, end);
if (!elements.empty() && !s_comma.ignore(pos, end))
break;
ws.ignore(pos, end);
elements.push_back(ASTRenameQuery::Element());
if (!parseDatabaseAndTable(elements.back().from, pos, end, max_parsed_pos, expected)
|| !s_to.ignore(pos, end)
|| !parseDatabaseAndTable(elements.back().to, pos, end, max_parsed_pos, expected))
return false;
}
auto query = std::make_shared<ASTRenameQuery>(StringRange(begin, pos));
node = query;
query->elements = elements;
return true;
}
}