implemented table alias

src/build_and_run_tests.sh

@@ -11,17 +11,17 @@ make grammar_test
 echo "\n\n"
 
 ./bin/grammar_test "SELECT a FROM foo WHERE a > 12 OR b > 3 AND c = 3 LIMIT 10"
-./bin/grammar_test "SELECT col1, col2, 'test' FROM table, foo WHERE age > 12 AND zipcode = 12345 GROUP BY col1;"
+./bin/grammar_test "SELECT col1, col2, 'test' FROM table, foo AS t WHERE age > 12 AND zipcode = 12345 GROUP BY col1;"
-./bin/grammar_test "SELECT age FROM table, (SELECT * FROM table2) ORDER BY age DESC"
+./bin/grammar_test "SELECT age FROM table AS t1, (SELECT * FROM table2) AS t2 ORDER BY age DESC"
-./bin/grammar_test "SELECT * from table WHERE (b OR NOT a) AND a = 12.5 JOIN table2 ON a = b"
+./bin/grammar_test "SELECT * from table WHERE (b OR NOT a) AND a = 12.5 AS t1 JOIN table2 ON a = b"
 
-./bin/grammar_test -f "(SELECT a FROM foo WHERE a > 12 OR b > 3 AND c = 3 LIMIT 10)"
+./bin/grammar_test "(SELECT a FROM foo WHERE a > 12 OR b > 3 AND c = 3 LIMIT 10)"
 
 echo "\n\n"
 
 # ./bin/analysis "SELECT a FROM foo WHERE a > 12 OR b > 3 AND c = 3"
-./bin/analysis "SELECT col1, col2, 'test' FROM table, foo WHERE age > 12 AND zipcode = 12345 GROUP BY col1 ORDER BY col2 DESC LIMIT 100;"
+./bin/analysis "SELECT col1, col2, 'test' FROM table t1, foo WHERE age > 12 AND zipcode = 12345 GROUP BY col1 ORDER BY col2 DESC LIMIT 100;"
-./bin/analysis "SELECT * from table WHERE (b OR NOT a) AND a = 12.5 JOIN table2 ON t1.a = t2.b"
+./bin/analysis "SELECT * from table WHERE (b OR NOT a) AND a = 12.5 AS t1 JOIN table2 AS t2 ON t1.a = t2.b"
 # ./bin/analysis "SELECT * from table WHERE (b OR NOT a) AND a = 12.5 JOIN table2 ON a = b"
 
 echo "\n\n"

src/lib/Table.h

@@ -26,6 +26,7 @@ struct TableRef {
 	TableRefType type;
 
 	char* name;
+	char* alias;
 	SelectStatement* select;
 	JoinStatement* join;
 	List<TableRef*>* list;

src/lib/sqlhelper.cpp

@@ -28,6 +28,10 @@ void printTableRefInfo(TableRef* table, uint num_indent) {
       for (TableRef* tbl : table->list->_vector) printTableRefInfo(tbl, num_indent);
       break;
   }
+  if (table->alias != NULL) {
+    inprint("Alias", num_indent+1);
+    inprint(table->alias, num_indent+2);
+  }
 }
 
 void printOperatorExpression(Expr* expr, uint num_indent) {
@@ -86,11 +90,13 @@ void printSelectStatementInfo(SelectStatement* stmt, uint num_indent) {
 
 void printJoinStatementInfo(JoinStatement* stmt, uint num_indent) {
   inprint("JoinStatement", num_indent);
-  inprint("Left Table", num_indent+1);
+  inprint("JoinType:", num_indent+1);
+  inprintU(stmt->join_type, num_indent+2);
+  inprint("Left Table:", num_indent+1);
   printTableRefInfo(stmt->left, num_indent+2);
-  inprint("Right Table", num_indent+1);
+  inprint("Right Table:", num_indent+1);
   printTableRefInfo(stmt->right, num_indent+2);
-  inprint("Join Condition", num_indent+1);
+  inprint("Join Condition:", num_indent+1);
   printExpression(stmt->join_condition, num_indent+2);
 }
 

src/parser/bison_parser.y

@@ -107,8 +107,9 @@ typedef void* yyscan_t;
 %type <statement> 	statement
 %type <select_stmt> select_statement
 %type <join_stmt>	join_statement
-%type <sval> 		table_name
+%type <sval> 		table_name opt_alias alias
-%type <table> 		from_clause table_ref table_ref_atomic table_ref_atomic_opt_paren
+%type <table> 		from_clause table_ref table_ref_atomic table_ref_name
+%type <table>		join_table
 %type <expr> 		expr scalar_expr unary_expr binary_expr function_expr star_expr
 %type <expr> 		column_name literal int_literal num_literal
 %type <expr> 		comp_expr where_clause join_condition
@@ -137,6 +138,7 @@ typedef void* yyscan_t;
 %left		'^'
 
 /* Unary Operators */
+%right 		UMINUS
 %left		'[' ']'
 %left		'(' ')'
 %left		'.'
@@ -168,7 +170,7 @@ statement:
  ******************************/
 
 join_statement:
-		table_ref_atomic_opt_paren JOIN table_ref_atomic_opt_paren ON join_condition
+		join_table JOIN join_table ON join_condition
 		{ 
 			$$ = new JoinStatement();
 			$$->left = $1;
@@ -178,6 +180,17 @@ join_statement:
 		}
 		;
 
+
+join_table:
+		select_statement alias {
+			auto tbl = new TableRef(kTableSelect);
+			tbl->select = $1;
+			tbl->alias = $2;
+			$$ = tbl;
+		}
+	|	table_ref_name;
+
+
 join_condition:
 		expr
 		;
@@ -199,6 +212,7 @@ select_statement:
 			s->limit = $7;
 			$$ = s;
 		}
+	|	'(' select_statement ')' { $$ = $2; }
 		;
 
 
@@ -326,15 +340,13 @@ table_ref:
 	}
 	;
 
+
 table_ref_atomic:
-		table_name {
+		table_ref_name
-			auto tbl = new TableRef(kTableName);
+	|	'(' select_statement ')' alias {
-			tbl->name = $1;
-			$$ = tbl;
-		}
-	|	'(' select_statement ')' {
 			auto tbl = new TableRef(kTableSelect);
 			tbl->select = $2;
+			tbl->alias = $4;
 			$$ = tbl;
 		}
 	;
@@ -346,23 +358,29 @@ table_ref_commalist:
 	;
 
 
-/* For join statements, where a select statement is allowed to be used without parenthesis */
+table_ref_name:
-table_ref_atomic_opt_paren:
+		table_name opt_alias {
-		table_ref_atomic
+			auto tbl = new TableRef(kTableName);
-	|	select_statement {
+			tbl->name = $1;
-			auto tbl = new TableRef(kTableSelect);
+			tbl->alias = $2;
-			tbl->select = $1;
 			$$ = tbl;
 		}
 		;
 
-
 table_name:
 		NAME
 	|	NAME '.' NAME
 	;
 
 
+alias:	
+		AS NAME { $$ = $2; }
+	|	NAME
+	;
+
+opt_alias:
+		alias
+	|	/* empty */ { $$ = NULL; }
 
 opt_semicolon:
 		';'

src/parser/flex_lexer.l

@@ -57,6 +57,7 @@ WHERE	TOKEN(WHERE)
 NOT		TOKEN(NOT)
 AND		TOKEN(AND)
 OR		TOKEN(OR)
+AS		TOKEN(AS)
 
 LIMIT	TOKEN(LIMIT)
 ORDER	TOKEN(ORDER)