Add capability for multi join table references (#40)

src/parser/bison_parser.y

@@ -188,7 +188,7 @@ int yyerror(YYLTYPE* llocp, SQLParserResult* result, yyscan_t scanner, const cha
 %type <bval> 		opt_not_exists opt_distinct
 %type <uval>		import_file_type opt_join_type column_type
 %type <table> 		from_clause table_ref table_ref_atomic table_ref_name
-%type <table>		join_clause join_table table_ref_name_no_alias
+%type <table>		join_clause table_ref_name_no_alias
 %type <expr> 		expr operand scalar_expr unary_expr binary_expr logic_expr exists_expr
 %type <expr>		function_expr between_expr star_expr expr_alias placeholder_expr
 %type <expr> 		column_name literal int_literal num_literal string_literal
@@ -225,11 +225,11 @@ int yyerror(YYLTYPE* llocp, SQLParserResult* result, yyscan_t scanner, const cha
 %left		'^'
 
 /* Unary Operators */
-%right 		UMINUS
+%right  UMINUS
 %left		'[' ']'
 %left		'(' ')'
 %left		'.'
-
+%left   JOIN
 %%
 /*********************************
  ** Section 3: Grammar Definition
@@ -817,7 +817,7 @@ opt_alias:
  ******************************/
 
 join_clause:
-		join_table opt_join_type JOIN join_table ON join_condition
+		table_ref_atomic opt_join_type JOIN table_ref_atomic ON join_condition
 		{ 
 			$$ = new TableRef(kTableJoin);
 			$$->join = new JoinDefinition();
@@ -841,17 +841,6 @@ opt_join_type:
 	;
 
 
-
-join_table:
-		'(' select_statement ')' alias {
-			auto tbl = new TableRef(kTableSelect);
-			tbl->select = $2;
-			tbl->alias = $4;
-			$$ = tbl;
-		}
-	|	table_ref_name;
-
-
 join_condition:
 		expr
 		;

test/select_tests.cpp

@@ -205,3 +205,45 @@ TEST(SelectCaseWhen) {
   ASSERT(caseExpr->expr->isSimpleOp('='));
   ASSERT_EQ(caseExpr->exprList->size(), 2);
 }
+
+TEST(SelectJoin) {
+  TEST_PARSE_SINGLE_SQL(
+    "SELECT City.name, Product.category, SUM(price) FROM fact\
+      INNER JOIN City ON fact.city_id = City.id\
+      OUTER JOIN Product ON fact.product_id = Product.id\
+      GROUP BY City.name, Product.category;",
+    kStmtSelect,
+    SelectStatement,
+    result,
+    stmt);
+
+  const TableRef* table = stmt->fromTable;
+  const JoinDefinition* outer_join = table->join;
+  ASSERT_EQ(table->type, kTableJoin);
+  ASSERT_EQ(outer_join->type, kJoinOuter);
+
+  ASSERT_EQ(outer_join->right->type, kTableName);
+  ASSERT_STREQ(outer_join->right->name, "Product");
+  ASSERT(outer_join->condition->isSimpleOp('='));
+  ASSERT_STREQ(outer_join->condition->expr->table, "fact");
+  ASSERT_STREQ(outer_join->condition->expr->name, "product_id");
+  ASSERT_STREQ(outer_join->condition->expr2->table, "Product");
+  ASSERT_STREQ(outer_join->condition->expr2->name, "id");
+
+  // Joins are are left associative.
+  // So the second join should be on the left.
+  ASSERT_EQ(outer_join->left->type, kTableJoin);
+
+  const JoinDefinition* inner_join = outer_join->left->join;
+  ASSERT_EQ(inner_join->type, kJoinInner);
+  ASSERT_EQ(inner_join->left->type, kTableName);
+  ASSERT_STREQ(inner_join->left->name, "fact");
+  ASSERT_EQ(inner_join->right->type, kTableName);
+  ASSERT_STREQ(inner_join->right->name, "City");
+
+  ASSERT(inner_join->condition->isSimpleOp('='));
+  ASSERT_STREQ(inner_join->condition->expr->table, "fact");
+  ASSERT_STREQ(inner_join->condition->expr->name, "city_id");
+  ASSERT_STREQ(inner_join->condition->expr2->table, "City");
+  ASSERT_STREQ(inner_join->condition->expr2->name, "id");
+}

test/valid_queries.sql

@@ -11,6 +11,7 @@ SELECT * FROM t1 UNION (SELECT * FROM t2 UNION SELECT * FROM t3) ORDER BY col1;
 SELECT TOP 10 * FROM t1 ORDER BY col1, col2;
 SELECT a, MAX(b), MAX(c, d), CUSTOM(q, UP(r)) AS f FROM t1;
 SELECT * FROM t WHERE a BETWEEN 1 and c;
+SELECT City.name, Product.category, SUM(price) FROM fact INNER JOIN City ON fact.city_id = City.id INNER JOIN Product ON fact.product_id = Product.id GROUP BY City.name, Product.category;
 # JOIN
 SELECT t1.a, t1.b, t2.c FROM "table" AS t1 JOIN (SELECT * FROM foo JOIN bar ON foo.id = bar.id) t2 ON t1.a = t2.b WHERE (t1.b OR NOT t1.a) AND t2.c = 12.5
 SELECT * FROM t1 JOIN t2 ON c1 = c2;