NULL need to be detected in COPY

src/sqlast.rs

@@ -223,6 +223,7 @@ impl ToString for ASTNode{
                                         .collect::<Vec<String>>().join("\t")
                                 );
                 }
+                s += "\n\\.";
                 s
             }
             ASTNode::SQLUpdate{table_name, assignments, selection} => {

src/sqlparser.rs

@@ -656,6 +656,10 @@ impl Parser {
                 Token::Backslash => {
                     if let Ok(true) = self.consume_token(&Token::Period) {
                         return Ok(values);
+                    }if let Some(token) = self.next_token(){
+                        if token == Token::Identifier("N".to_string()){
+                            values.push(Value::Null);
+                        }
                     }else{
                         continue;
                     }

src/sqlparser/tests.rs

@@ -558,9 +558,11 @@ Kwara & Kogi
 {"Deleted Scenes","Behind the Scenes"}
 'awe':5 'awe-inspir':4 'barbarella':1 'cat':13 'conquer':16 'dog':18 'feminist':10 'inspir':6 'monasteri':21 'must':15 'stori':7 'streetcar':2
 PHP	₱ USD $
+\N  Some other value
 \\."#);
     let ast = parse_sql(&sql);
-    //assert_eq!(sql, ast.to_string());
+    println!("{:#?}", ast);
+    assert_eq!(sql, ast.to_string());
 }
 
 #[test]