Support WITH (#125)

* Add struct WithDescription in SelectStatement.h

* Add test for With statements

* Implement With draft

* tm

* Fix Grammar

* Fix commented code

* naming improvements

* naming improvements

* introduce memory leak1

* removed memory leak

* Create two WITH-tests

* Add bad queries reg. WITH

src/parser/bison_parser.h

@@ -255,6 +255,7 @@ union HSQL_STYPE
 	hsql::Expr* expr;
 	hsql::OrderDescription* order;
 	hsql::OrderType order_type;
+	hsql::WithDescription* with_description_t;
 	hsql::DatetimeField datetime_field;
 	hsql::LimitDescription* limit;
 	hsql::ColumnDefinition* column_t;
@@ -271,8 +272,9 @@ union HSQL_STYPE
 	std::vector<hsql::UpdateClause*>* update_vec;
 	std::vector<hsql::Expr*>* expr_vec;
 	std::vector<hsql::OrderDescription*>* order_vec;
+	std::vector<hsql::WithDescription*>* with_description_vec;
 
-#line 276 "bison_parser.h" /* yacc.c:1909  */
+#line 278 "bison_parser.h" /* yacc.c:1909  */
 };
 
 typedef union HSQL_STYPE HSQL_STYPE;

src/parser/bison_parser.y

@@ -116,6 +116,7 @@ int yyerror(YYLTYPE* llocp, SQLParserResult* result, yyscan_t scanner, const cha
 	hsql::Expr* expr;
 	hsql::OrderDescription* order;
 	hsql::OrderType order_type;
+	hsql::WithDescription* with_description_t;
 	hsql::DatetimeField datetime_field;
 	hsql::LimitDescription* limit;
 	hsql::ColumnDefinition* column_t;
@@ -132,6 +133,7 @@ int yyerror(YYLTYPE* llocp, SQLParserResult* result, yyscan_t scanner, const cha
 	std::vector<hsql::UpdateClause*>* update_vec;
 	std::vector<hsql::Expr*>* expr_vec;
 	std::vector<hsql::OrderDescription*>* order_vec;
+	std::vector<hsql::WithDescription*>* with_description_vec;
 }
 
 
@@ -212,11 +214,13 @@ int yyerror(YYLTYPE* llocp, SQLParserResult* result, yyscan_t scanner, const cha
 %type <update_t>	    update_clause
 %type <group_t>		    opt_group
 %type <alias_t>		    opt_table_alias table_alias opt_alias alias
+%type <with_description_t>  with_description
 
 %type <str_vec>			ident_commalist opt_column_list
 %type <expr_vec> 		expr_list select_list opt_literal_list literal_list hint_list opt_hints
 %type <table_vec> 		table_ref_commalist
 %type <order_vec>		opt_order order_list
+%type <with_description_vec> 	opt_with_clause with_clause with_description_list
 %type <update_vec>		update_clause_commalist
 %type <column_vec>		column_def_commalist
 
@@ -583,20 +587,27 @@ update_clause:
  ******************************/
 
 select_statement:
-		select_with_paren
+		opt_with_clause select_with_paren {
-	|	select_no_paren
+			$$ = $2;
-	|	select_with_paren set_operator select_paren_or_clause opt_order opt_limit {
+			$$->withDescriptions = $1;
+		}
+	|	opt_with_clause select_no_paren {
+			$$ = $2;
+			$$->withDescriptions = $1;
+		}
+	|	opt_with_clause select_with_paren set_operator select_paren_or_clause opt_order opt_limit {
 			// TODO: allow multiple unions (through linked list)
 			// TODO: capture type of set_operator
 			// TODO: might overwrite order and limit of first select here
-			$$ = $1;
+			$$ = $2;
-			$$->unionSelect = $3;
+			$$->withDescriptions = $1;
-			$$->order = $4;
+			$$->unionSelect = $4;
+			$$->order = $5;
 
 			// Limit could have been set by TOP.
-			if ($5 != nullptr) {
+			if ($6 != nullptr) {
 				delete $$->limit;
-				$$->limit = $5;
+				$$->limit = $6;
 			}
 		}
 	;
@@ -1012,6 +1023,39 @@ opt_alias:
 	|	/* empty */ { $$ = nullptr; }
 
 
+/******************************
+ * With Descriptions
+ ******************************/
+
+opt_with_clause:
+		with_clause
+	| 	/* empty */ { $$ = nullptr; }
+	;
+
+with_clause:
+		WITH with_description_list { $$ = $2; }
+	;
+
+with_description_list:
+		with_description {
+			$$ = new std::vector<WithDescription*>();
+			$$->push_back($1);
+		}
+	|	with_description_list ',' with_description {
+			$1->push_back($3);
+                        $$ = $1;
+		}
+	;
+
+with_description:
+		IDENTIFIER AS select_with_paren {
+			$$ = new WithDescription();
+			$$->alias = $1;
+			$$->select = $3;
+		}
+	;
+
+
 /******************************
  * Join Statements
  ******************************/

src/sql/SelectStatement.h

@@ -39,6 +39,13 @@ namespace hsql {
     Expr* having;
   };
 
+  struct WithDescription {
+      ~WithDescription();
+
+      char* alias;
+      SelectStatement* select;
+  };
+
   // Representation of a full SQL select statement.
   // TODO: add union_order and union_limit.
   struct SelectStatement : SQLStatement {
@@ -53,9 +60,11 @@ namespace hsql {
 
     SelectStatement* unionSelect;
     std::vector<OrderDescription*>* order;
+    std::vector<WithDescription*>* withDescriptions;
     LimitDescription* limit;
   };
 
+
 } // namespace hsql
 
 #endif

src/sql/statements.cpp

@@ -227,6 +227,11 @@ namespace hsql {
     }
   }
 
+  WithDescription::~WithDescription() {
+    free(alias);
+    delete select;
+  }
+
   // SelectStatement
   SelectStatement::SelectStatement() :
     SQLStatement(kStmtSelect),
@@ -237,6 +242,7 @@ namespace hsql {
     groupBy(nullptr),
     unionSelect(nullptr),
     order(nullptr),
+    withDescriptions(nullptr),
     limit(nullptr) {};
 
   SelectStatement::~SelectStatement() {
@@ -260,6 +266,13 @@ namespace hsql {
       }
       delete order;
     }
+
+    if (withDescriptions != nullptr) {
+      for (WithDescription* desc : *withDescriptions) {
+        delete desc;
+      }
+      delete withDescriptions;
+    }
   }
 
   // UpdateStatement

test/queries/queries-bad.sql

@@ -10,3 +10,7 @@
 !SELECT * FROM t WHERE a = ? AND b = ?;gibberish;
 !SHOW COLUMNS;
 !select a + 2 as b(spam, eggs) from B;
+!WITH a AS SELECT 1 SELECT 1;
+!WITH a AS (SELECT ) SELECT 1;
+!WITH a AS (WITH b AS (SELECT 1) SELECT 1) SELECT 1; # We do not support nested WITH clauses
+!WITH a AS (SELECT ) b AS (SELECT ) SELECT 1; # Missing comma between WITH descriptions

test/select_tests.cpp

@@ -681,3 +681,60 @@ TEST(NoFromClause) {
   ASSERT_EQ(stmt->selectList->at(0)->expr->type, kExprLiteralInt);
   ASSERT_EQ(stmt->selectList->at(0)->expr2->type, kExprLiteralInt);
 }
+
+
+TEST(WithClauseSingle) {
+  TEST_PARSE_SINGLE_SQL("WITH "
+                        "a AS (SELECT name FROM peopleA)"
+                        "SELECT name FROM a;",
+                        kStmtSelect,
+                        SelectStatement,
+                        result,
+                        stmt)
+
+  // with_description_list – count
+  ASSERT_EQ(stmt->withDescriptions->size(), 1);
+
+  // with_description – alias
+  ASSERT_STREQ(stmt->withDescriptions->at(0)->alias, "a");
+
+  // with_description – select stmt
+  ASSERT_EQ(stmt->withDescriptions->at(0)->select->selectList->size(), 1)
+  ASSERT_STREQ(stmt->withDescriptions->at(0)->select->selectList->at(0)->name,  std::string("name"));
+  ASSERT_STREQ(stmt->withDescriptions->at(0)->select->fromTable->name,  std::string("peopleA"));
+
+  // main select
+  ASSERT_EQ(stmt->selectList->size(), 1);
+  ASSERT_STREQ(stmt->selectList->at(0)->name, "name");
+  ASSERT_STREQ(stmt->fromTable->name, "a");
+
+}
+
+TEST(WithClauseDouble) {
+  TEST_PARSE_SINGLE_SQL("WITH "
+                        "a AS (SELECT nameA FROM peopleA), "
+                        "b AS (SELECT nameB, cityB FROM peopleB) "
+                        "SELECT nameA FROM a;",
+                        kStmtSelect,
+                        SelectStatement,
+                        result,
+                        stmt)
+
+  // with_description_list – count
+  ASSERT_EQ(stmt->withDescriptions->size(), 2);
+
+  // with_description – aliases
+  ASSERT_STREQ(stmt->withDescriptions->at(0)->alias, "a");
+  ASSERT_STREQ(stmt->withDescriptions->at(1)->alias, "b");
+
+  // with_description – select stmts
+  ASSERT_EQ(stmt->withDescriptions->at(0)->select->selectList->size(), 1)
+  ASSERT_STREQ(stmt->withDescriptions->at(0)->select->fromTable->name, "peopleA");
+  ASSERT_EQ(stmt->withDescriptions->at(1)->select->selectList->size(), 2)
+  ASSERT_STREQ(stmt->withDescriptions->at(1)->select->fromTable->name, "peopleB");
+
+  // main select
+  ASSERT_EQ(stmt->selectList->size(), 1);
+  ASSERT_STREQ(stmt->selectList->at(0)->name, "nameA");
+  ASSERT_STREQ(stmt->fromTable->name, "a");
+}