diff --git a/lexer/lexer.mll b/lexer/lexer.mll
index 4dec155..946bf27 100644
--- a/lexer/lexer.mll
+++ b/lexer/lexer.mll
@@ -16,12 +16,16 @@ rule read_token = parse
   | "COUNT"     { COUNT }
   | "DISTINCT"  { DISTINCT }
   | "FROM"      { FROM }
+  | "INNER"     { INNER }
   | "LEFT"      { LEFT }
   | "RIGHT"     { RIGHT }
   | "CROSS"     { CROSS }
   | "UNION"     { UNION }
+  | "NATURAL"   { NATURAL }
   | "JOIN"      { JOIN }
   | "ON"        { ON }
+  | "OR"        { OR }
+  | "AND"       { AND }
   | "WHERE"     { WHERE }
   | "HAVING"    { HAVING }
   | "BETWEEN"   { BETWEEN }
@@ -36,6 +40,12 @@ rule read_token = parse
   | ")"         { RIGHT_PAREN }
   | ","         { COMMA }
   | "|"         { PIPE }
+  | "'"         { QUOTE }
+  | "+"         { PLUS_SIGN }
+  | "-"         { MINUS_SIGN }
   | whitespace  { read_token lexbuf }
+  | digit+      { INTEGER }
+  | digit+"."digit+ { FLOAT }
+  | '.'digit+   { FLOAT }
   | alpha alphanumeric* as ident      { IDENT ident }
   | eof         { EOF }