Fix style error and test cases error

src/Interpreters/CollectJoinOnKeysVisitor.cpp

@@ -80,6 +80,9 @@ void CollectJoinOnKeysMatcher::visit(const ASTFunction & func, const ASTPtr & as
         ASTPtr right = func.arguments->children.at(1);
         auto table_numbers = getTableNumbers(left, right, data);
 
+        if (table_numbers.first != table_numbers.second && table_numbers.first > 0 && table_numbers.second > 0)
+            data.new_on_expression_valid = true;
+
         /**
           * if this is an inner join and the expression related to less than 2 tables, then move it to WHERE
           */
@@ -108,6 +111,9 @@ void CollectJoinOnKeysMatcher::visit(const ASTFunction & func, const ASTPtr & as
             ASTPtr right = func.arguments->children.at(1);
             auto table_numbers = getTableNumbers(left, right, data);
 
+            if (table_numbers.first != table_numbers.second && table_numbers.first > 0 && table_numbers.second > 0)
+                data.new_on_expression_valid = true;
+
             if (data.kind == ASTTableJoin::Kind::Inner
                 && (table_numbers.first == table_numbers.second || table_numbers.first == 0 || table_numbers.second == 0))
             {

src/Interpreters/CollectJoinOnKeysVisitor.h

@@ -37,6 +37,7 @@ public:
         ASTPtr new_on_expression{};
         ASTPtr new_where_conditions{};
         bool has_some{false};
+        bool new_on_expression_valid{false};
 
         void addJoinKeys(const ASTPtr & left_ast, const ASTPtr & right_ast, const std::pair<size_t, size_t> & table_no);
         void addAsofJoinKeys(const ASTPtr & left_ast, const ASTPtr & right_ast, const std::pair<size_t, size_t> & table_no,

src/Interpreters/TreeRewriter.cpp

@@ -425,6 +425,9 @@ void collectJoinedColumns(TableJoin & analyzed_join, const ASTSelectQuery & sele
                             ErrorCodes::INVALID_JOIN_ON_EXPRESSION);
         if (is_asof)
             data.asofToJoinKeys();
+        else if (!data.new_on_expression_valid)
+            throw Exception("JOIN expects left and right joined keys from two joined table in ON section. Unexpected '" + queryToString(data.new_on_expression) + "'",
+                ErrorCodes::INVALID_JOIN_ON_EXPRESSION);
         else if (data.new_where_conditions != nullptr)
         {
             table_join.on_expression = data.new_on_expression;

tests/queries/0_stateless/00878_join_unexpected_results.reference

@@ -23,6 +23,7 @@ join_use_nulls = 1
 -
 \N	\N
 -
+1	1	\N	\N
 2	2	\N	\N
 -
 1	1	1	1
@@ -50,6 +51,7 @@ join_use_nulls = 0
 -
 -
 -
+1	1	0	0
 2	2	0	0
 -
 1	1	1	1