fix: make field lookups case-insensitive and use explicit table alias key in mapper

Author: wilburhimself

src/main/java/io/retrorock/theory/helpers/ModelMapper.java

@@ -235,7 +235,7 @@ public ModelMapper fields(Class entity, String alias) {
 
     public ModelMapper fields(Class entity) {
         Map<String, String> tableInfo = getTableinfo(entity);
-        this.fields(entity, tableInfo.get(tableAlias));
+        this.fields(entity, tableInfo.get("tableAlias"));
         return this;
     }
 

src/main/java/io/retrorock/theory/helpers/RowMapperHelper.java

@@ -16,8 +16,9 @@ public RowMapperHelper(ResultSet resultSet) throws SQLException {
     public Boolean fieldExists(String fieldName) throws SQLException {
         Boolean result = false;
         for (int i = 1; i <= this.metaData.getColumnCount(); i ++) {
-            if (metaData.getColumnLabel(i).equals(fieldName)) {
-                Object fieldObject = resultSet.getObject(fieldName);
+            String label = metaData.getColumnLabel(i);
+            if (label != null && label.equalsIgnoreCase(fieldName)) {
+                Object fieldObject = resultSet.getObject(label);
                 if (fieldObject != null) {
                     result = true;
                 }