diff --git a/parser/parser.mly b/parser/parser.mly
index e79cef8..702ee22 100644
--- a/parser/parser.mly
+++ b/parser/parser.mly
@@ -19,8 +19,11 @@ open Ast
 %token AS ON GROUP BY FILTER
 %token OR AND NOT 
 %token TRUE FALSE UNKNOWN
-%token PLUS_SIGN MINUS_SIGN INTEGER FLOAT
-%token UNDERSCORE QUOTE
+%token PLUS_SIGN MINUS_SIGN 
+%token DATE TIME TIMESTAMP
+%token <int> INTEGER 
+%token FLOAT
+%token UNDERSCORE QUOTE COLON
 %token EOF
 %start main
 %type <query> main
@@ -48,18 +51,19 @@ greater_than_or_equals_operator:
 
 (* 5.3 LITERAL *)
 literal :
-  | signed_numeric_literal {}
-  | general_literal {}
+  | signed_numeric_literal { $1 }
+  | general_literal { $1 }
 
 unsigned_literal:
 (*  | unsigned_numeric_literal {}*)
-  | general_literal {}
+  | general_literal { $1 }
 
 general_literal:
-  | character_string_literal {}
+  | character_string_literal { $1 }
+  | datetime_literal { $1 }
 
 character_string_literal:
-  | QUOTE IDENT QUOTE {}
+  | QUOTE IDENT QUOTE { StringLiteral($2) }
 
 introducer:
   | UNDERSCORE { }
@@ -78,12 +82,65 @@ sign:
   | PLUS_SIGN {}
   | MINUS_SIGN {}
 
+unsigned_integer:
+  | INTEGER { $1 }
+
+datetime_literal:
+  | date_literal { $1 }
+  | time_literal { $1 }
+  (*| timestamp_literal {}*)
+
+date_literal:
+  | DATE date_string { DateLiteral($2) }
+
+time_literal:
+  | TIME time_string { TimeLiteral($2) }
+
+date_string:
+  | QUOTE unquoted_date_string QUOTE { $2 }
+
+time_string:
+  | QUOTE unquoted_time_string QUOTE { $2 }
+
+date_value:
+  | years_value MINUS_SIGN months_value MINUS_SIGN days_value { String.concat "-" [$1;$3;$5] }
+
+time_value:
+  | hours_value COLON minutes_value COLON seconds_value { String.concat ":" [$1;$3;$5] }
+
+unquoted_date_string:
+  | date_value { $1 }
+
+unquoted_time_string:
+  | time_value { $1 }
+
+years_value :
+  | datetime_value { $1 }
+
+months_value :
+  | datetime_value { $1 }
+
+days_value :
+  | datetime_value { $1 }
+
+hours_value :
+  | datetime_value { $1 }
+
+minutes_value :
+  | datetime_value { $1 }
+
+seconds_value:
+  | datetime_value { $1 }
+
+datetime_value :
+  | unsigned_integer { string_of_int $1 }
+
 (***********)
 
 (* 5.4 NAMES AND IDENTIFIER *)
 
 column_name :
-  | IDENT {}
+  | IDENT { $1 }
 
 table_name :
   | IDENT { Table($1) }
@@ -110,6 +167,7 @@ parenthesized_value_expression:
   | LEFT_PAREN value_expression RIGHT_PAREN { $2 }
 
 nonparenthesized_value_expression_primary:
+  | unsigned_value_specification { $1 }
   | column_reference { Ref($1) }
   (*| set_function_specification { Ref("function") } *)
 
@@ -118,8 +176,8 @@ nonparenthesized_value_expression_primary:
 (* 6.4 VALUE SPECIFCATION / TARGET SPECIFICATION *)
 
 unsigned_value_specification:
-  | unsigned_literal {}
-  | general_value_specification {}
+  | unsigned_literal { $1 }
+  (*| general_value_specification {}*)
 
 general_value_specification:
   | {}
@@ -155,7 +213,7 @@ set_function_specification:
 (* 6.25 VALUE EXPRESSION *)
 
 value_expression:
-  | common_value_expression {}
+  | common_value_expression { $1 }
 
 common_value_expression:
   (*| numeric_value_expression {}*)
@@ -170,7 +228,7 @@ reference_value_expression:
 (* 6.28 STRING VALUE EXPRESSION *)
 
 string_value_expression :
-  | character_value_expression {} 
+  | character_value_expression { $1 } 
   (* | blob_value_expression {} *)
 
 character_primary:
@@ -264,8 +322,9 @@ row_value_special_case :
 (* 7.4 TABLE EXPRESSION *)
 
 table_expression:
-  | from_clause { $1 }
-  | from_clause where_clause { $1 }
+  | { None }
+  | from_clause { Some($1) }
+  | from_clause where_clause { Some($1) }
 
 (************************)
 
@@ -395,15 +454,21 @@ query_specification :
 
 select_list :
   | ASTERISK { [Asterisk] }
-  | select_sublist {$1}
+  | select_sublist { $1 }
 
+(*
 select_sublist :
   | IDENT { [Column($1)] }
   | select_sublist COMMA IDENT { Column($3)::$1 }
+*)
+
+select_sublist :
+  | select_sublist_element { [$1] }
+  | select_sublist COMMA select_sublist_element { $3::$1 }
 
 select_sublist_element :
-  | derived_column {}
-  | qualified_asterisk {}
+  | derived_column { $1 }
+(*  | qualified_asterisk {} *)
 
 qualified_asterisk:
   | asterisked_identifier_chain {}
@@ -416,12 +481,12 @@ asterisked_identifier :
   | IDENT {}
 
 derived_column:
-  | value_expression {}
-  | value_expression as_clause {}
+  | value_expression { Column($1, None) }
+  | value_expression as_clause { Column($1, Some($2)) }
 
 as_clause :
-  | AS column_name {}
-  | column_name {}
+  | AS column_name { As($2) }
+  (*| column_name { As($1) }*)
 
 (****************************)
 
@@ -537,31 +602,31 @@ search_condition:
 (* 10.9 AGGREGATE FUNCTION *)
 
 aggregate_function:
-  | COUNT LEFT_PAREN ASTERISK RIGHT_PAREN { }
-  | COUNT LEFT_PAREN ASTERISK RIGHT_PAREN filter_clause { }
-  | general_set_function { }
-  | general_set_function filter_clause { }
+  | COUNT LEFT_PAREN ASTERISK RIGHT_PAREN { Count }
+  | COUNT LEFT_PAREN ASTERISK RIGHT_PAREN filter_clause { Count }
+  | general_set_function { Aggregate($1) }
+  | general_set_function filter_clause { Aggregate($1, $2) }
 
 general_set_function:
-  | set_function_type LEFT_PAREN value_expression RIGHT_PAREN { }
-  | set_function_type LEFT_PAREN set_quantifier value_expression RIGHT_PAREN { }
+  | set_function_type LEFT_PAREN value_expression RIGHT_PAREN { Function($1, None, $3)  }
+  | set_function_type LEFT_PAREN set_quantifier value_expression RIGHT_PAREN { Function($1, $3, $4) }
 
 set_function_type:
-  | computationnal_operation {}
+  | computationnal_operation { $1 }
 
 set_quantifier :
-  | ALL {}
-  | DISTINCT {}
+  | ALL { All }
+  | DISTINCT { Distinct }
 
 filter_clause :
-  | FILTER LEFT_PAREN WHERE search_condition RIGHT_PAREN {}
+  | FILTER LEFT_PAREN WHERE search_condition RIGHT_PAREN { Filter($4) }
 
 computationnal_operation:
-  | AVG {}
-  | MAX {}
-  | MIN {}
-  | SUM {}
-  | COUNT {}
+  | AVG { Avg }
+  | MAX { Max }
+  | MIN { Min }
+  | SUM { Sum }
+  | COUNT { Count }
 
 (***************************)