ClickHouse/dbms/src/Parsers/ParserSetQuery.cpp
2012-08-02 19:03:32 +00:00

94 lines
1.7 KiB
C++

#include <DB/Parsers/ASTIdentifier.h>
#include <DB/Parsers/ASTLiteral.h>
#include <DB/Parsers/ASTSetQuery.h>
#include <DB/Parsers/CommonParsers.h>
#include <DB/Parsers/ParserSetQuery.h>
namespace DB
{
/// Парсит name = value.
static bool parseNameValuePair(ASTSetQuery::Change & change, IParser::Pos & pos, IParser::Pos end, String & expected)
{
ParserIdentifier name_p;
ParserLiteral value_p;
ParserWhiteSpaceOrComments ws;
ParserString s_eq("=");
ASTPtr name;
ASTPtr value;
ws.ignore(pos, end);
if (!name_p.parse(pos, end, name, expected))
return false;
ws.ignore(pos, end);
if (!s_eq.ignore(pos, end, expected))
return false;
ws.ignore(pos, end);
if (!value_p.parse(pos, end, value, expected))
return false;
ws.ignore(pos, end);
change.name = dynamic_cast<const ASTIdentifier &>(*name).name;
change.value = dynamic_cast<const ASTLiteral &>(*value).value;
return true;
}
bool ParserSetQuery::parseImpl(Pos & pos, Pos end, ASTPtr & node, String & expected)
{
Pos begin = pos;
ParserWhiteSpaceOrComments ws;
ParserString s_set("SET", true, true);
ParserString s_global("GLOBAL", true, true);
ParserString s_comma(",");
ws.ignore(pos, end);
if (!s_set.ignore(pos, end, expected))
return false;
ws.ignore(pos, end);
bool global = s_global.ignore(pos, end, expected);
ASTSetQuery::Changes changes;
while (true)
{
ws.ignore(pos, end);
if (!changes.empty() && !s_comma.ignore(pos, end))
break;
ws.ignore(pos, end);
changes.push_back(ASTSetQuery::Change());
if (!parseNameValuePair(changes.back(), pos, end, expected))
return false;
}
ASTSetQuery * query = new ASTSetQuery(StringRange(begin, pos));
node = query;
query->changes = changes;
query->global = global;
return true;
}
}