[jOOQ/jOOQ#14215] Plain SQL INSERT .. RETURNING doesn't work with unqualified field templates in SQL Server

See also [jOOQ/jOOQ#14218]

jOOQ/src/main/java/org/jooq/impl/SQLField.java

@@ -45,12 +45,12 @@ import org.jooq.impl.QOM.UEmptyField;
 
 final class SQLField<T> extends AbstractField<T> implements UEmptyField<T>, TypedReference<T> {
 
-    private final QueryPart delegate;
+    final SQLImpl delegate;
 
     SQLField(DataType<T> type, SQL delegate) {
         super(DSL.unquotedName(delegate.toString()), type);
 
-        this.delegate = delegate;
+        this.delegate = (SQLImpl) delegate;
     }
 
     // ------------------------------------------------------------------------

jOOQ/src/main/java/org/jooq/impl/SQLImpl.java

@@ -54,12 +54,28 @@ import org.jooq.impl.QOM.UEmpty;
 final class SQLImpl extends AbstractQueryPart implements SQL, UEmpty {
 
     private static final Clause[] CLAUSES = { TEMPLATE };
-    private final String          sql;
-    private final List<QueryPart> substitutes;
+    final String                  sql;
+    final boolean                 isName;
+    final List<QueryPart>         substitutes;
 
     SQLImpl(String sql, Object... input) {
         this.sql = requireNonNull(sql);
         this.substitutes = Tools.queryParts(input);
+        this.isName = substitutes.isEmpty() && isName(sql);
+    }
+
+    static final boolean isName(String sql) {
+        int l = sql.length();
+
+        // [#14215] Good enough approximation of SQL identifiers
+        if (l == 0 || !Character.isJavaIdentifierStart(sql.charAt(0)))
+            return false;
+
+        for (int i = 1; i < l; i++)
+            if (!Character.isJavaIdentifierPart(sql.charAt(i)))
+                return false;
+
+        return true;
     }
 
     @Override

jOOQ/src/main/java/org/jooq/impl/Tools.java

@@ -1686,6 +1686,11 @@ final class Tools {
         return result;
     }
 
+    static final boolean reference(Field<?> field) {
+        return field instanceof TableField
+            || field instanceof SQLField && ((SQLField<?>) field).delegate.isName;
+    }
+
     static final <T> Field<T> unqualified(Field<T> field) {
         return DSL.field(field.getUnqualifiedName(), field.getDataType());
     }