Query works fine in MySql but returns no records with JdbcTemplate - spring

Question

I have the following service method:
public Page<ProductSalesReportLineDto> getReport(
Unit unit, Organization customer, Organization supplier, Date startDate, Date endDate, Pageable pageable
){
List<ProductSalesReportLineDto> lines = new ArrayList<ProductSalesReportLineDto>();
String sql = "SELECT product.id, product.code as code, product.barcode as barcode, product_name.name__text AS name, " +
"SUM(order_line.quantity) as quantity, SUM(order_line.commissioned_price_price * order_line.quantity) as price " +
"FROM product LEFT JOIN order_line ON order_line.product_id = product.id " +
"JOIN `order` ON order_line.order_id = order.id " +
"JOIN product_name ON product_name.product_id = product.id " +
"WHERE product_name.name__locale = \"en-US\" " +
"AND (:customer is null OR :customer='' OR `order`.customer_id = :customer) " +
"AND (:supplier is null OR :supplier='' OR `order`.supplier_id = :supplier) " +
"AND (:startDate is null OR :startDate='' OR `order`.date >= :startDate) " +
"AND (:endDate is null OR :endDate='' OR `order`.date <= :endDate) " +
"AND (:unit is null OR :unit='' OR product.unit = :unit) " +
"GROUP BY product.id, product_name.name__text " +
"LIMIT :offset, :pageSize";
Map<String, Object> parameters = new HashMap<String, Object>();
parameters.put("offset", pageable.getOffset());
parameters.put("pageSize", pageable.getPageSize());
parameters.put("customer", customer != null ? customer.id : null);
parameters.put("supplier", supplier != null ? supplier.id : null);
parameters.put("startDate", startDate);
parameters.put("endDate", endDate);
parameters.put("unit", unit);
List<Map<String, Object>> rows = namedParameterJdbcTemplate.queryForList(sql, parameters);
for (Map<String, Object> row : rows) {
ProductSalesReportLineDto line = new ProductSalesReportLineDto();
line.productName = row.get("name") != null ? row.get("name").toString() : "";
line.productCode = row.get("code") != null ? row.get("code").toString() : "";
line.productBarcode = row.get("barcode") != null ? row.get("barcode").toString() : "";
line.quantity = row.get("quantity") != null ? Double.parseDouble(row.get("quantity").toString()) : 0;
line.price = row.get("price") != null ? Double.parseDouble(row.get("price").toString()) : 0;
lines.add(line);
}
Page<ProductSalesReportLineDto> page = new PageImpl<ProductSalesReportLineDto>(lines);
return page;
}
The parameters come from a #RestController method:
public #ResponseBody
ResponseEntity<?> get(
#RequestParam(value = "unit", required = false) Unit unit,
#RequestParam(value = "customer", required = false) Organization customer,
#RequestParam(value = "supplier", required = false) Organization supplier,
#DateTimeFormat(pattern = "yyyyy-MM-dd") #RequestParam(value = "startDate", required = false) Date startDate,
#DateTimeFormat(pattern = "yyyyy-MM-dd") #RequestParam(value = "endDate", required = false) Date endDate,
Pageable pageable
)
And Unit is an enum type field on Product:
#Enumerated(EnumType.STRING)
public Unit unit;
public enum Unit {
ROLL("ROLL", "ROLL", AbstractUnit.ONE),
METRE("METRE", Units.METRE.getSymbol(), Units.METRE),
KILOGRAM("KILOGRAM", Units.KILOGRAM.getSymbol(), Units.KILOGRAM),
PIECE("PIECE", "PIECE", AbstractUnit.ONE),
SAMPLE("SAMPLE", "SAMPLE", AbstractUnit.ONE);
I cannot retrieve products by unit using this query. With MySql the query works fine and it returns records. For example:
SELECT product.id, product.code as code, product.barcode as barcode, product_name.name__text AS name, SUM(order_line.quantity) as quantity, SUM(order_line.commissioned_price_price) as price FROM product LEFT JOIN order_line ON order_line.product_id = product.id JOIN `order` ON order_line.order_id = `order`.id JOIN product_name ON product_name.product_id = product.id WHERE product_name.name__locale = "en-US" AND (null is null OR null='' OR `order`.customer_id = null) AND (null is null OR null='' OR `order`.supplier_id = null) AND (null is null OR null='' OR `order`.date >= null) AND (null is null OR null='' OR `order`.date <= null) AND ("ROLL" is null OR "ROLL"='' OR product.unit = "ROLL") GROUP BY product.id, product_name.name__text
This query returns one row. When I run the same query via the rest interface and NamedParameterJdbcTemplate it returns no records. Can anybody tell what I am missing?
Following code also returns one row:
String sql2 = "SELECT * FROM product WHERE product.unit = :unit";
Map<String, Object> parameters2 = new HashMap<String, Object>();
parameters2.put("unit", "ROLL");
List<Map<String, Object>> rows2 = namedParameterJdbcTemplate.queryForList(sql2, parameters2);