dbms: fixed error; parsing 'ON' expression in JOINs [#METR-18692].

dbms/include/DB/Parsers/ASTJoin.h

@@ -42,6 +42,7 @@ public:
 
 	ASTPtr table;				/// "Правая" таблица для соединения - подзапрос или имя таблицы.
 	ASTPtr using_expr_list;		/// По каким столбцам выполнять соединение.
+	ASTPtr on_expr;				/// Условие соединения. Поддерживается либо USING либо ON, но не одновременно.
 
 	ASTJoin() = default;
 	ASTJoin(const StringRange range_) : IAST(range_) {}
@@ -108,11 +109,16 @@ protected:
 
 		table->formatImpl(settings, state, frame);
 
-		if (kind != ASTJoin::Cross)
+		if (using_expr_list)
 		{
 			settings.ostr << (settings.hilite ? hilite_keyword : "") << " USING " << (settings.hilite ? hilite_none : "");
 			using_expr_list->formatImpl(settings, state, frame);
 		}
+		else if (on_expr)
+		{
+			settings.ostr << (settings.hilite ? hilite_keyword : "") << " ON " << (settings.hilite ? hilite_none : "");
+			on_expr->formatImpl(settings, state, frame);
+		}
 	}
 };
 

dbms/src/Parsers/ParserJoin.cpp

@@ -28,8 +28,10 @@ bool ParserJoin::parseImpl(Pos & pos, Pos end, ASTPtr & node, Pos & max_parsed_p
 	ParserString s_outer("OUTER", true, true);
 	ParserString s_join("JOIN", true, true);
 	ParserString s_using("USING", true, true);
+	ParserString s_on("ON", true, true);
 
 	ParserNotEmptyExpressionList exp_list(false);
+	ParserLogicalOrExpression exp_elem;
 	ParserWithOptionalAlias subquery(ParserPtr(new ParserSubquery), true);
 	ParserIdentifier identifier;
 
@@ -93,15 +95,41 @@ bool ParserJoin::parseImpl(Pos & pos, Pos end, ASTPtr & node, Pos & max_parsed_p
 
 	if (join->kind != ASTJoin::Cross)
 	{
-		if (!s_using.ignore(pos, end, max_parsed_pos, expected))
+		if (s_using.ignore(pos, end, max_parsed_pos, expected))
+		{
+			ws.ignore(pos, end);
+
+			/// Выражение для USING можно указать как в скобках, так и без них.
+			bool in_parens = ParserString("(").ignore(pos, end);
+			if (in_parens)
+				ws.ignore(pos, end);
+
+			if (!exp_list.parse(pos, end, join->using_expr_list, max_parsed_pos, expected))
+				return false;
+
+			ws.ignore(pos, end);
+
+			if (in_parens)
+			{
+				ws.ignore(pos, end);
+				if (!ParserString(")").ignore(pos, end))
+					return false;
+			}
+		}
+		else if (s_on.ignore(pos, end, max_parsed_pos, expected))
+		{
+			ws.ignore(pos, end);
+
+			if (!exp_elem.parse(pos, end, join->on_expr, max_parsed_pos, expected))
+				return false;
+
+			ws.ignore(pos, end);
+		}
+		else
+		{
+			expected = "USING or ON";
 			return false;
-
-		ws.ignore(pos, end);
-
-		if (!exp_list.parse(pos, end, join->using_expr_list, max_parsed_pos, expected))
-			return false;
-
-		ws.ignore(pos, end);
+		}
 	}
 
 	join->children.push_back(join->table);

dbms/src/Parsers/ParserSelectQuery.cpp

@@ -113,6 +113,9 @@ bool ParserSelectQuery::parseImpl(Pos & pos, Pos end, ASTPtr & node, Pos & max_p
 				if (s_dot.ignore(pos, end, max_parsed_pos, expected))
 				{
 					select_query->database = select_query->table;
+
+					ws.ignore(pos, end);
+
 					if (!ident.parse(pos, end, select_query->table, max_parsed_pos, expected))
 						return false;
 

dbms/tests/queries/0_stateless/00269_database_table_whitespace.reference

@@ -0,0 +1,2 @@
+0
+0

dbms/tests/queries/0_stateless/00269_database_table_whitespace.sql

@@ -0,0 +1,2 @@
+SELECT * FROM system . one;
+SELECT * FROM system /* Hello */. `one`;