Merge pull request #4598 from 4ertus2/ast

Fix CrossToInnerJoin rewrite

dbms/src/Interpreters/CrossToInnerJoinVisitor.cpp

@@ -192,6 +192,9 @@ void CrossToInnerJoinMatcher::visit(ASTSelectQuery & select, ASTPtr & ast, Data
     using CheckExpressionMatcher = OneTypeMatcher<CheckExpressionVisitorData, false>;
     using CheckExpressionVisitor = InDepthNodeVisitor<CheckExpressionMatcher, true>;
 
+    if (!select.where_expression)
+        return;
+
     std::vector<DatabaseAndTableWithAlias> table_names;
     ASTPtr ast_join = getCrossJoin(select, table_names);
     if (!ast_join)
@@ -215,10 +218,10 @@ void CrossToInnerJoinMatcher::visit(ASTSelectQuery & select, ASTPtr & ast, Data
             select.where_expression.reset();
 
         join.children.push_back(join.on_expression);
+
+        ast = ast->clone(); /// rewrite AST in right manner
+        data.done = true;
     }
-
-    ast = ast->clone(); /// rewrite AST in right manner
-    data.done = true;
 }
 
 }

dbms/tests/queries/0_stateless/00826_cross_to_inner_join.reference

@@ -1,3 +1,5 @@
+0	0
+0	0
 cross
 1	1	1	1
 1	1	1	2
@@ -67,7 +69,7 @@ Explain ParsedAST (children 1)\n SelectWithUnionQuery (children 1)\n  Expression
 Explain ParsedAST (children 1)\n SelectWithUnionQuery (children 1)\n  ExpressionList (children 1)\n   SelectQuery (children 2)\n    ExpressionList (children 1)\n     Asterisk\n    TablesInSelectQuery (children 2)\n     TablesInSelectQueryElement (children 1)\n      TableExpression (children 1)\n       Identifier t1 (alias x)\n     TablesInSelectQueryElement (children 2)\n      TableJoin (children 1)\n       Function and (children 1)\n        ExpressionList (children 2)\n         Function equals (children 1)\n          ExpressionList (children 2)\n           Identifier x.a\n           Identifier y.a\n         Function equals (children 1)\n          ExpressionList (children 2)\n           Identifier x.b\n           Identifier y.b\n      TableExpression (children 1)\n       Identifier t1 (alias y)\n
 cross one table expr
 Explain ParsedAST (children 1)\n SelectWithUnionQuery (children 1)\n  ExpressionList (children 1)\n   SelectQuery (children 3)\n    ExpressionList (children 1)\n     Asterisk\n    TablesInSelectQuery (children 2)\n     TablesInSelectQueryElement (children 1)\n      TableExpression (children 1)\n       Identifier t1\n     TablesInSelectQueryElement (children 2)\n      TableExpression (children 1)\n       Identifier t2\n      TableJoin\n    Function equals (children 1)\n     ExpressionList (children 2)\n      Identifier t1.a\n      Identifier t1.b\n
-Explain ParsedAST (children 1)\n SelectWithUnionQuery (children 1)\n  ExpressionList (children 1)\n   SelectQuery (children 3)\n    ExpressionList (children 1)\n     Asterisk\n    TablesInSelectQuery (children 2)\n     TablesInSelectQueryElement (children 1)\n      TableExpression (children 1)\n       Identifier t1\n     TablesInSelectQueryElement (children 2)\n      TableJoin\n      TableExpression (children 1)\n       Identifier t2\n    Function equals (children 1)\n     ExpressionList (children 2)\n      Identifier t1.a\n      Identifier t1.b\n
+Explain ParsedAST (children 1)\n SelectWithUnionQuery (children 1)\n  ExpressionList (children 1)\n   SelectQuery (children 3)\n    ExpressionList (children 1)\n     Asterisk\n    TablesInSelectQuery (children 2)\n     TablesInSelectQueryElement (children 1)\n      TableExpression (children 1)\n       Identifier t1\n     TablesInSelectQueryElement (children 2)\n      TableExpression (children 1)\n       Identifier t2\n      TableJoin\n    Function equals (children 1)\n     ExpressionList (children 2)\n      Identifier t1.a\n      Identifier t1.b\n
 cross multiple ands
 Explain ParsedAST (children 1)\n SelectWithUnionQuery (children 1)\n  ExpressionList (children 1)\n   SelectQuery (children 3)\n    ExpressionList (children 1)\n     Asterisk\n    TablesInSelectQuery (children 2)\n     TablesInSelectQueryElement (children 1)\n      TableExpression (children 1)\n       Identifier t1\n     TablesInSelectQueryElement (children 2)\n      TableExpression (children 1)\n       Identifier t2\n      TableJoin\n    Function and (children 1)\n     ExpressionList (children 2)\n      Function equals (children 1)\n       ExpressionList (children 2)\n        Identifier t1.a\n        Identifier t2.a\n      Function equals (children 1)\n       ExpressionList (children 2)\n        Identifier t1.b\n        Identifier t2.b\n
 Explain ParsedAST (children 1)\n SelectWithUnionQuery (children 1)\n  ExpressionList (children 1)\n   SelectQuery (children 2)\n    ExpressionList (children 1)\n     Asterisk\n    TablesInSelectQuery (children 2)\n     TablesInSelectQueryElement (children 1)\n      TableExpression (children 1)\n       Identifier t1\n     TablesInSelectQueryElement (children 2)\n      TableJoin (children 1)\n       Function and (children 1)\n        ExpressionList (children 2)\n         Function equals (children 1)\n          ExpressionList (children 2)\n           Identifier t1.a\n           Identifier t2.a\n         Function equals (children 1)\n          ExpressionList (children 2)\n           Identifier t1.b\n           Identifier t2.b\n      TableExpression (children 1)\n       Identifier t2\n

dbms/tests/queries/0_stateless/00826_cross_to_inner_join.sql

@@ -1,6 +1,11 @@
 SET enable_debug_queries = 1;
 USE test;
 
+set allow_experimental_cross_to_join_conversion = 0;
+select * from system.one cross join system.one;
+set allow_experimental_cross_to_join_conversion = 1;
+select * from system.one cross join system.one;
+
 DROP TABLE IF EXISTS t1;
 DROP TABLE IF EXISTS t2;