Fix COLLATE parsing after compound identifiers

Move the COLLATE parsing from the end of `parse_prefix` to
`parse_subexpr` after `parse_compound_expr`, so that `expr COLLATE
collation` is handled correctly when `expr` is a compound identifier
(e.g. `t1.col COLLATE Latin1_General_CI_AS`).

Author: Roman Borschel

src/parser/mod.rs

@@ -1394,6 +1394,13 @@ impl<'a> Parser<'a> {
 
         expr = self.parse_compound_expr(expr, vec![])?;
 
+        if !self.in_column_definition_state() && self.parse_keyword(Keyword::COLLATE) {
+            expr = Expr::Collate {
+                expr: Box::new(expr),
+                collation: self.parse_object_name(false)?,
+            };
+        }
+
         debug!("prefix: {expr:?}");
         loop {
             let next_precedence = self.get_next_precedence()?;
@@ -1935,14 +1942,7 @@ impl<'a> Parser<'a> {
             _ => self.expected_at("an expression", next_token_index),
         }?;
 
-        if !self.in_column_definition_state() && self.parse_keyword(Keyword::COLLATE) {
-            Ok(Expr::Collate {
-                expr: Box::new(expr),
-                collation: self.parse_object_name(false)?,
-            })
-        } else {
-            Ok(expr)
-        }
+        Ok(expr)
     }
 
     fn parse_geometric_type(&mut self, kind: GeometricTypeKind) -> Result<Expr, ParserError> {

tests/sqlparser_mssql.rs

@@ -2860,3 +2860,8 @@ fn parse_mssql_update_with_output_into() {
         "UPDATE employees SET salary = salary * 1.1 OUTPUT INSERTED.id, DELETED.salary, INSERTED.salary INTO @changes WHERE department = 'Engineering'",
     );
 }
+
+#[test]
+fn test_collate_on_compound_identifier() {
+    tsql().verified_stmt("SELECT t1.a COLLATE Latin1_General_CI_AS FROM t1");
+}