Merge pull request #79 from f4lco/table-alias-with-columns

Extend table alias with column renames: "AS tbl(c0, c1)"

src/parser/bison_parser.h

@@ -48,7 +48,7 @@
 extern int hsql_debug;
 #endif
 /* "%code requires" blocks.  */
-#line 35 "bison_parser.y" /* yacc.c:1915  */
+#line 35 "bison_parser.y" /* yacc.c:1909  */
 
 // %code requires block
 
@@ -72,7 +72,7 @@ extern int hsql_debug;
 				} \
 		}
 
-#line 76 "bison_parser.h" /* yacc.c:1915  */
+#line 76 "bison_parser.h" /* yacc.c:1909  */
 
 /* Token type.  */
 #ifndef HSQL_TOKENTYPE
@@ -218,7 +218,7 @@ extern int hsql_debug;
 
 union HSQL_STYPE
 {
-#line 95 "bison_parser.y" /* yacc.c:1915  */
+#line 95 "bison_parser.y" /* yacc.c:1909  */
 
 	double fval;
 	int64_t ival;
@@ -247,6 +247,7 @@ union HSQL_STYPE
 	hsql::ColumnDefinition* column_t;
 	hsql::GroupByDescription* group_t;
 	hsql::UpdateClause* update_t;
+	hsql::Alias* alias_t;
 
 	std::vector<hsql::SQLStatement*>* stmt_vec;
 
@@ -257,7 +258,7 @@ union HSQL_STYPE
 	std::vector<hsql::Expr*>* expr_vec;
 	std::vector<hsql::OrderDescription*>* order_vec;
 
-#line 261 "bison_parser.h" /* yacc.c:1915  */
+#line 262 "bison_parser.h" /* yacc.c:1909  */
 };
 
 typedef union HSQL_STYPE HSQL_STYPE;

src/parser/bison_parser.y

@@ -120,6 +120,7 @@ int yyerror(YYLTYPE* llocp, SQLParserResult* result, yyscan_t scanner, const cha
 	hsql::ColumnDefinition* column_t;
 	hsql::GroupByDescription* group_t;
 	hsql::UpdateClause* update_t;
+	hsql::Alias* alias_t;
 
 	std::vector<hsql::SQLStatement*>* stmt_vec;
 
@@ -133,7 +134,7 @@ int yyerror(YYLTYPE* llocp, SQLParserResult* result, yyscan_t scanner, const cha
 
 
 /*********************************
- ** Descrutor symbols
+ ** Destructor symbols
  *********************************/
 %destructor { } <fval> <ival> <uval> <bval> <order_type>
 %destructor { free( ($$.name) ); free( ($$.schema) ); } <table_name>
@@ -189,7 +190,7 @@ int yyerror(YYLTYPE* llocp, SQLParserResult* result, yyscan_t scanner, const cha
 %type <drop_stmt>	drop_statement
 %type <show_stmt>	show_statement
 %type <table_name>  table_name
-%type <sval> 		opt_alias alias file_path prepare_target_query
+%type <sval> 		file_path prepare_target_query
 %type <bval> 		opt_not_exists opt_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 nonjoin_table_ref_atomic
@@ -205,6 +206,7 @@ int yyerror(YYLTYPE* llocp, SQLParserResult* result, yyscan_t scanner, const cha
 %type <column_t>	column_def
 %type <update_t>	update_clause
 %type <group_t>		opt_group
+%type <alias_t>		opt_table_alias table_alias opt_alias alias
 
 %type <str_vec>		ident_commalist opt_column_list
 %type <expr_vec> 	expr_list select_list literal_list hint_list opt_hints
@@ -735,7 +737,10 @@ literal_list:
 expr_alias:
 		expr opt_alias {
 			$$ = $1;
-			$$->alias = $2;
+			if ($2) {
+				$$->alias = strdup($2->name);
+				delete $2;
+			}
 		}
 	;
 
@@ -906,7 +911,7 @@ table_ref_atomic:
 
 nonjoin_table_ref_atomic:
 		table_ref_name
-	|	'(' select_statement ')' opt_alias {
+	|	'(' select_statement ')' opt_table_alias {
 			auto tbl = new TableRef(kTableSelect);
 			tbl->select = $2;
 			tbl->alias = $4;
@@ -921,7 +926,7 @@ table_ref_commalist:
 
 
 table_ref_name:
-		table_name opt_alias {
+		table_name opt_table_alias {
 			auto tbl = new TableRef(kTableName);
 			tbl->schema = $1.schema;
 			tbl->name = $1.name;
@@ -946,11 +951,23 @@ table_name:
 	;
 
 
-alias:
+table_alias:
-		AS IDENTIFIER { $$ = $2; }
+		alias
-	|	IDENTIFIER
+	|	AS IDENTIFIER '(' ident_commalist ')' { $$ = new Alias($2, $4); }
 	;
 
+
+opt_table_alias:
+		table_alias
+	|	/* empty */ { $$ = nullptr; }
+
+
+alias:
+		AS IDENTIFIER { $$ = new Alias($2); }
+	|	IDENTIFIER { $$ = new Alias($1); }
+	;
+
+
 opt_alias:
 		alias
 	|	/* empty */ { $$ = nullptr; }
@@ -1037,4 +1054,3 @@ ident_commalist:
  *********************************/
 
 /* empty */
-

src/sql/Table.h

@@ -24,6 +24,14 @@ namespace hsql {
     char* name;
   };
 
+  struct Alias {
+    Alias(char* name, std::vector<char*>* columns = nullptr);
+    ~Alias();
+
+    char* name;
+    std::vector<char*>* columns;
+  };
+
   // Holds reference to tables. Can be either table names or a select statement.
   struct TableRef {
     TableRef(TableRefType type);
@@ -33,7 +41,7 @@ namespace hsql {
 
     char* schema;
     char* name;
-    char* alias;
+    Alias* alias;
 
     SelectStatement* select;
     std::vector<TableRef*>* list;

src/sql/statements.cpp

@@ -231,6 +231,21 @@ namespace hsql {
     }
   }
 
+  // Alias
+  Alias::Alias(char* name, std::vector<char*>* columns) :
+    name(name),
+    columns(columns) {}
+
+  Alias::~Alias() {
+    free(name);
+    if (columns) {
+      for (char* column : *columns) {
+        free(column);
+      }
+      delete columns;
+    }
+  }
+
   // TableRef
   TableRef::TableRef(TableRefType type) :
     type(type),
@@ -244,10 +259,10 @@ namespace hsql {
   TableRef::~TableRef() {
     free(schema);
     free(name);
-    free(alias);
 
     delete select;
     delete join;
+    delete alias;
 
     if (list != nullptr) {
       for (TableRef* table : *list) {
@@ -262,7 +277,7 @@ namespace hsql {
   }
 
   const char* TableRef::getName() const {
-    if (alias != nullptr) return alias;
+    if (alias) return alias->name;
     else return name;
   }
 

src/util/sqlhelper.cpp

@@ -6,6 +6,7 @@
 namespace hsql {
 
   void printOperatorExpression(Expr* expr, uintmax_t numIndent);
+  void printAlias(Alias* alias, uintmax_t numIndent);
 
   std::string indent(uintmax_t numIndent) {
     return std::string(numIndent, '\t');
@@ -54,9 +55,20 @@ namespace hsql {
       for (TableRef* tbl : *table->list) printTableRefInfo(tbl, numIndent);
       break;
     }
-    if (table->alias != nullptr) {
+
+    if (table->alias) {
+      printAlias(table->alias, numIndent);
+    }
+  }
+
+  void printAlias(Alias* alias, uintmax_t numIndent) {
     inprint("Alias", numIndent + 1);
-      inprint(table->alias, numIndent + 2);
+    inprint(alias->name, numIndent + 2);
+
+    if (alias->columns) {
+      for (char* column : *(alias->columns)) {
+        inprint(column, numIndent + 3);
+      }
     }
   }
 

test/queries/queries-bad.sql

@@ -10,3 +10,4 @@
 !INSERT INTO test_table VALUESd (1, 2, 'test');
 !SELECT * FROM t WHERE a = ? AND b = ?;SELECT 1;
 !SHOW COLUMNS;
+!select a + 2 as b(spam, eggs) from B;

test/queries/tpc-h-13.sql

@@ -3,6 +3,6 @@ SELECT C_COUNT, COUNT(*) AS CUSTDIST
 FROM (SELECT C_CUSTKEY, COUNT(O_ORDERKEY)
  FROM CUSTOMER left outer join ORDERS on C_CUSTKEY = O_CUSTKEY
  AND O_COMMENT not like '%%special%%requests%%'
- GROUP BY C_CUSTKEY) AS C_ORDERS
+ GROUP BY C_CUSTKEY) AS C_ORDERS (C_CUSTKEY, C_COUNT)
 GROUP BY C_COUNT
 ORDER BY CUSTDIST DESC, C_COUNT DESC;

test/select_tests.cpp

@@ -343,9 +343,55 @@ TEST(SelectColumnOrder) {
 
   // Make sure the order of the table list is corrects
   ASSERT_STREQ(stmt->fromTable->list->at(0)->name, "a");
-  ASSERT_STREQ(stmt->fromTable->list->at(1)->alias, "b");
+  ASSERT_STREQ(stmt->fromTable->list->at(1)->alias->name, "b");
-  ASSERT_STREQ(stmt->fromTable->list->at(2)->alias, "c");
+  ASSERT_STREQ(stmt->fromTable->list->at(2)->alias->name, "c");
-  ASSERT_STREQ(stmt->fromTable->list->at(3)->alias, "d");
+  ASSERT_STREQ(stmt->fromTable->list->at(3)->alias->name, "d");
+}
+
+
+TEST(SelectAliasAbsent) {
+  TEST_PARSE_SINGLE_SQL(
+    "SELECT * FROM students;",
+    kStmtSelect,
+    SelectStatement,
+    result,
+    stmt);
+
+    ASSERT_NULL(stmt->fromTable->alias);
+}
+
+TEST(SelectAliasSimple) {
+  TEST_PARSE_SINGLE_SQL(
+    "SELECT * FROM students AS s1;",
+    kStmtSelect,
+    SelectStatement,
+    result,
+    stmt);
+
+    Alias* alias = stmt->fromTable->alias;
+    ASSERT_NOTNULL(alias);
+    ASSERT_STREQ(alias->name, "s1");
+    ASSERT_NULL(alias->columns);
+}
+
+TEST(SelectAliasWithColumns) {
+  TEST_PARSE_SINGLE_SQL(
+    "SELECT * FROM students AS s1(id, city);",
+    kStmtSelect,
+    SelectStatement,
+    result,
+    stmt);
+
+    Alias* alias = stmt->fromTable->alias;
+    ASSERT_NOTNULL(alias);
+
+    ASSERT_NOTNULL(alias->name);
+    ASSERT_STREQ(alias->name, "s1");
+
+    ASSERT_NOTNULL(alias->columns);
+    ASSERT_EQ(alias->columns->size(), 2);
+    ASSERT_STREQ(alias->columns->at(0), "id");
+    ASSERT_STREQ(alias->columns->at(1), "city");
 }
 
 TEST(Operators) {