add support for [NOT] NULL in xml columns

Author: lovasoa

src/ast/query.rs

@@ -3142,8 +3142,8 @@ pub enum XmlTableColumnOption {
         path: Option<Expr>,
         /// Default value if path does not match
         default: Option<Expr>,
-        // TODO: Add NULL ON EMPTY / ERROR handling if needed later
-        // TODO: Add NOT NULL / NULL constraints
+        /// Whether the column is nullable (NULL=true, NOT NULL=false)
+        nullable: bool,
     },
     /// The FOR ORDINALITY marker
     ForOrdinality,
@@ -3179,6 +3179,7 @@ impl fmt::Display for XmlTableColumn {
                 r#type,
                 path,
                 default,
+                nullable,
             } => {
                 write!(f, " {}", r#type)?;
                 if let Some(p) = path {
@@ -3187,6 +3188,9 @@ impl fmt::Display for XmlTableColumn {
                 if let Some(d) = default {
                     write!(f, " DEFAULT {}", d)?;
                 }
+                if !*nullable {
+                    write!(f, " NOT NULL")?;
+                }
                 Ok(())
             }
             XmlTableColumnOption::ForOrdinality => {

src/parser/mod.rs

@@ -12378,12 +12378,17 @@ impl<'a> Parser<'a> {
                 default = Some(self.parse_expr()?);
             }
 
-            // TODO: Parse NOT NULL/NULL constraints
+            let not_null = self.parse_keywords(&[Keyword::NOT, Keyword::NULL]);
+            if !not_null {
+                // NULL is the default but can be specified explicitly
+                let _ = self.parse_keyword(Keyword::NULL);
+            }
 
             XmlTableColumnOption::NamedInfo {
                 r#type,
                 path,
                 default,
+                nullable: !not_null,
             }
         };
         Ok(XmlTableColumn { name, option })

tests/sqlparser_common.rs

@@ -11742,6 +11742,11 @@ fn test_xmltable() {
     // Test using subqueries
     all_dialects().verified_only_select("SELECT y FROM XMLTABLE((SELECT '/X') PASSING (SELECT CAST('<X><y>z</y></X>' AS xml)) COLUMNS y TEXT PATH (SELECT 'y'))");
 
+    // NOT NULL
+    all_dialects().verified_only_select(
+        "SELECT y FROM XMLTABLE('/X' PASSING '<X></X>' COLUMNS y TEXT NOT NULL)",
+    );
+
     all_dialects().verified_only_select("SELECT * FROM XMLTABLE('/root/row' PASSING xmldata COLUMNS id INT PATH '@id', name TEXT PATH 'name/text()', value FLOAT PATH 'value')");
 
     all_dialects().verified_only_select("SELECT * FROM XMLTABLE('//ROWS/ROW' PASSING data COLUMNS row_num FOR ORDINALITY, id INT PATH '@id', name TEXT PATH 'NAME' DEFAULT 'unnamed')");