bool ParserAliasImpl<ParserIdentifier>::parseImpl(Pos & pos, Pos end, ASTPtr & node, Pos & max_parsed_pos, Expected & expected)
{
ParserWhiteSpaceOrComments ws;
ParserString s_as("AS", true, true);
ParserIdentifier id_p;
bool has_as_word = s_as.parse(pos, end, node, max_parsed_pos, expected);
if (!allow_alias_without_as_keyword && !has_as_word)
return false;
ws.ignore(pos, end);
if (!id_p.parse(pos, end, node, max_parsed_pos, expected))
return false;
if (!has_as_word)
{
/** В этом случае алиас не может совпадать с ключевым словом - для того,
* чтобы в запросе "SELECT x FROM t", слово FROM не считалось алиасом,
* а в запросе "SELECT x FRO FROM t", слово FRO считалось алиасом.
*/
const String & name = static_cast<const ASTIdentifier &>(*node.get()).name;
for (const char ** keyword = restricted_keywords; *keyword != nullptr; ++keyword)
if (0 == strcasecmp(name.data(), *keyword))
return false;
}
return true;
}
bool ParserCreateQuery::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
ParserKeyword s_create("CREATE");
ParserKeyword s_temporary("TEMPORARY");
ParserKeyword s_attach("ATTACH");
ParserKeyword s_table("TABLE");
ParserKeyword s_database("DATABASE");
ParserKeyword s_if_not_exists("IF NOT EXISTS");
ParserKeyword s_as("AS");
ParserKeyword s_view("VIEW");
ParserKeyword s_materialized("MATERIALIZED");
ParserKeyword s_populate("POPULATE");
ParserToken s_dot(TokenType::Dot);
ParserToken s_lparen(TokenType::OpeningRoundBracket);
ParserToken s_rparen(TokenType::ClosingRoundBracket);
ParserStorage storage_p;
ParserIdentifier name_p;
ParserColumnsOrIndicesDeclarationList columns_or_indices_p;
ParserSelectWithUnionQuery select_p;
ASTPtr database;
ASTPtr table;
ASTPtr columns_list;
ASTPtr to_database;
ASTPtr to_table;
ASTPtr storage;
ASTPtr as_database;
ASTPtr as_table;
ASTPtr select;
String cluster_str;
bool attach = false;
bool if_not_exists = false;
bool is_view = false;
bool is_materialized_view = false;
bool is_populate = false;
bool is_temporary = false;
if (!s_create.ignore(pos, expected))
{
if (s_attach.ignore(pos, expected))
attach = true;
else
return false;
}
if (s_temporary.ignore(pos, expected))
{
is_temporary = true;
}
if (s_table.ignore(pos, expected))
{
if (s_if_not_exists.ignore(pos, expected))
if_not_exists = true;
if (!name_p.parse(pos, table, expected))
return false;
if (s_dot.ignore(pos, expected))
{
database = table;
if (!name_p.parse(pos, table, expected))
return false;
}
if (ParserKeyword{"ON"}.ignore(pos, expected))
{
if (!ASTQueryWithOnCluster::parse(pos, cluster_str, expected))
return false;
}
// Shortcut for ATTACH a previously detached table
if (attach && (!pos.isValid() || pos.get().type == TokenType::Semicolon))
{
auto query = std::make_shared<ASTCreateQuery>();
node = query;
query->attach = attach;
query->if_not_exists = if_not_exists;
query->cluster = cluster_str;
getIdentifierName(database, query->database);
getIdentifierName(table, query->table);
return true;
}
/// List of columns.
if (s_lparen.ignore(pos, expected))
{
if (!columns_or_indices_p.parse(pos, columns_list, expected))
return false;
if (!s_rparen.ignore(pos, expected))
return false;
if (!storage_p.parse(pos, storage, expected) && !is_temporary)
return false;
}
else
{
storage_p.parse(pos, storage, expected);
if (!s_as.ignore(pos, expected))
return false;
if (!select_p.parse(pos, select, expected)) /// AS SELECT ...
{
/// AS [db.]table
if (!name_p.parse(pos, as_table, expected))
return false;
if (s_dot.ignore(pos, expected))
{
as_database = as_table;
if (!name_p.parse(pos, as_table, expected))
return false;
}
/// Optional - ENGINE can be specified.
if (!storage)
storage_p.parse(pos, storage, expected);
}
}
}
else if (is_temporary)
return false;
else if (s_database.ignore(pos, expected))
{
if (s_if_not_exists.ignore(pos, expected))
if_not_exists = true;
if (!name_p.parse(pos, database, expected))
return false;
if (ParserKeyword{"ON"}.ignore(pos, expected))
{
if (!ASTQueryWithOnCluster::parse(pos, cluster_str, expected))
return false;
}
storage_p.parse(pos, storage, expected);
}
else
{
/// VIEW or MATERIALIZED VIEW
if (s_materialized.ignore(pos, expected))
{
is_materialized_view = true;
}
else
is_view = true;
if (!s_view.ignore(pos, expected))
return false;
if (s_if_not_exists.ignore(pos, expected))
if_not_exists = true;
if (!name_p.parse(pos, table, expected))
return false;
if (s_dot.ignore(pos, expected))
{
database = table;
if (!name_p.parse(pos, table, expected))
return false;
}
if (ParserKeyword{"ON"}.ignore(pos, expected))
{
if (!ASTQueryWithOnCluster::parse(pos, cluster_str, expected))
return false;
}
// TO [db.]table
if (ParserKeyword{"TO"}.ignore(pos, expected))
{
if (!name_p.parse(pos, to_table, expected))
return false;
if (s_dot.ignore(pos, expected))
{
to_database = to_table;
if (!name_p.parse(pos, to_table, expected))
return false;
}
}
/// Optional - a list of columns can be specified. It must fully comply with SELECT.
if (s_lparen.ignore(pos, expected))
{
if (!columns_or_indices_p.parse(pos, columns_list, expected))
return false;
if (!s_rparen.ignore(pos, expected))
return false;
}
if (is_materialized_view && !to_table)
{
/// Internal ENGINE for MATERIALIZED VIEW must be specified.
if (!storage_p.parse(pos, storage, expected))
return false;
if (s_populate.ignore(pos, expected))
is_populate = true;
}
/// AS SELECT ...
if (!s_as.ignore(pos, expected))
return false;
if (!select_p.parse(pos, select, expected))
return false;
}
auto query = std::make_shared<ASTCreateQuery>();
node = query;
query->attach = attach;
query->if_not_exists = if_not_exists;
query->is_view = is_view;
query->is_materialized_view = is_materialized_view;
query->is_populate = is_populate;
query->temporary = is_temporary;
getIdentifierName(database, query->database);
getIdentifierName(table, query->table);
query->cluster = cluster_str;
getIdentifierName(to_database, query->to_database);
getIdentifierName(to_table, query->to_table);
query->set(query->columns_list, columns_list);
query->set(query->storage, storage);
getIdentifierName(as_database, query->as_database);
getIdentifierName(as_table, query->as_table);
query->set(query->select, select);
return true;
}