Postgres: Support TRIM FROM syntax

src/parser/mod.rs

@@ -3101,6 +3101,21 @@ impl<'a> Parser<'a> {
                 trim_where = Some(self.parse_trim_where()?);
             }
         }
+        if self.dialect.supports_comma_separated_trim() && self.parse_keyword(Keyword::FROM) {
+            let expr = self.parse_expr()?;
+            let trim_characters = if self.consume_token(&Token::Comma) {
+                Some(self.parse_comma_separated(Parser::parse_expr)?)
+            } else {
+                None
+            };
+            self.expect_token(&Token::RParen)?;
+            return Ok(Expr::Trim {
+                expr: Box::new(expr),
+                trim_where,
+                trim_what: None,
+                trim_characters,
+            });
+        }
         let expr = self.parse_expr()?;
         if self.parse_keyword(Keyword::FROM) {
             let trim_what = Box::new(expr);
@@ -3118,7 +3133,7 @@ impl<'a> Parser<'a> {
             self.expect_token(&Token::RParen)?;
             Ok(Expr::Trim {
                 expr: Box::new(expr),
-                trim_where: None,
+                trim_where,
                 trim_what: None,
                 trim_characters: Some(characters),
             })

tests/sqlparser_common.rs

@@ -8528,6 +8528,11 @@ fn parse_trim() {
         expr_from_projection(only(&select.projection))
     );
 
+    dialects.one_statement_parses_to(
+        "SELECT TRIM(BOTH FROM 'yxTomxx', 'xyz')",
+        "SELECT TRIM(BOTH 'yxTomxx', 'xyz')",
+    );
+
     // dialects without comma-style TRIM syntax should fail
     let unsupported_dialects = all_dialects_where(|d| !d.supports_comma_separated_trim());
     assert_eq!(
@@ -8536,6 +8541,12 @@ fn parse_trim() {
             .parse_sql_statements("SELECT TRIM('xyz', 'a')")
             .unwrap_err()
     );
+    assert_eq!(
+        ParserError::ParserError("Expected: ), found: 'xyz'".to_owned()),
+        unsupported_dialects
+            .parse_sql_statements("SELECT TRIM(FROM 'xyz')")
+            .unwrap_err()
+    );
 }
 
 #[test]

tests/sqlparser_postgres.rs

@@ -9931,3 +9931,8 @@ fn parse_non_reserved_keywords_as_table_alias() {
         ));
     }
 }
+
+#[test]
+fn parse_trim_from_without_characters() {
+    pg().one_statement_parses_to("SELECT TRIM(FROM ' x ')", "SELECT TRIM(' x ')");
+}