adding filter to SELEC

lib/ast.ml

@@ -1,6 +1,6 @@
 type query = Query of select_stmt
 and select_stmt = 
-  | Select of column list * table list
+  | Select of column list * table list * filter option
 and column = 
   | Asterisk
   | Column of string
@@ -27,6 +27,7 @@ and predicate =
   | In of string list
   | NotIn of string list
   | Like of string
+  | NotLike of string
 and operator =
   | Equals
   | NotEquals
@@ -35,19 +36,17 @@ and operator =
   | LessEquals
   | GreaterEquals
 and filter = 
-  | Filter of string
+  | Filter of condition
 and search_condition =
   | Search of string
 
-
-
 let rec pp_query fmt ast = 
   match ast with
   | Query(s) ->  Format.fprintf fmt "%s" (pp_select s)
 
 and pp_select s = 
   match s with
-  | Select(cols, _) -> pp_columns cols
+  | Select(cols, _, _) -> pp_columns cols
 
 and pp_columns cols =
   match cols with
@@ -81,4 +80,3 @@ and pp_join_type j =
   | Union -> "union"
   | Natural -> "natural"
 
-