Support INTERVAL as argument. (#40)

Author: zdenal

src/parser/mod.rs

@@ -830,8 +830,7 @@ impl<'a> Parser<'a> {
                 Keyword::TRIM => self.parse_trim_expr(),
                 Keyword::INTERVAL
                     if self.peek_token().token != Token::Period
-                        && self.peek_token().token != Token::Comma
-                        && self.maybe_parse(|parser| parser.parse_interval()).is_some() =>
+                        && self.peek_token().token != Token::Comma =>
                 {
                     self.parse_interval()
                 }

tests/sqlparser_common.rs

@@ -4181,6 +4181,7 @@ fn parse_interval() {
     verified_only_select("SELECT INTERVAL '1' MINUTE TO SECOND");
     verified_only_select("SELECT INTERVAL '1 YEAR'");
     verified_only_select("SELECT INTERVAL '1 YEAR' AS one_year");
+    verified_only_select("SELECT date_sub(now(), INTERVAL 10 DAY)");
     one_statement_parses_to(
         "SELECT INTERVAL '1 YEAR' one_year",
         "SELECT INTERVAL '1 YEAR' AS one_year",