Always reproduced:

```
milovidov-desktop :) create table table_map (a Map(String, String), b String) engine = MergeTree() order by a;

CREATE TABLE table_map
(
    `a` Map(String, String),
    `b` String
)
ENGINE = MergeTree
ORDER BY a

Query id: 8f8120c1-c165-452a-815f-2bcae3957e2a

Ok.

0 rows in set. Elapsed: 0.002 sec. 

milovidov-desktop :) SELECT b FROM table_map WHERE a = map('name', NULL, '', NULL)

SELECT b
FROM table_map
WHERE a = {'name', NULL, '', NULL}
```
if constexpr (IsDataTypeDecimal<FromDataType> && IsDataTypeDecimal<ToDataType>)
                                convert_result = tryConvertDecimals<FromDataType, ToDataType>(vec_from[i], vec_from.getScale(), vec_to.getScale(), result);
                            else if constexpr (IsDataTypeDecimal<FromDataType> && IsDataTypeNumber<ToDataType>)
                                convert_result = tryConvertFromDecimal<FromDataType, ToDataType>(vec_from[i], vec_from.getScale(), result);
                            else if constexpr (IsDataTypeNumber<FromDataType> && IsDataTypeDecimal<ToDataType>)
                                convert_result = tryConvertToDecimal<FromDataType, ToDataType>(vec_from[i], vec_to.getScale(), result);
                            if (convert_result)
                                vec_to[i] = result;
                            else
                            {
                                vec_to[i] = static_cast<ToFieldType>(0);
                                (*vec_null_map_to)[i] = true;
                            }
                        }
                        else
                        {
                            if constexpr (IsDataTypeDecimal<FromDataType> && IsDataTypeDecimal<ToDataType>)
                                vec_to[i] = convertDecimals<FromDataType, ToDataType>(vec_from[i], vec_from.getScale(), vec_to.getScale());
                            else if constexpr (IsDataTypeDecimal<FromDataType> && IsDataTypeNumber<ToDataType>)
                                vec_to[i] = convertFromDecimal<FromDataType, ToDataType>(vec_from[i], vec_from.getScale());
                            else if constexpr (IsDataTypeNumber<FromDataType> && IsDataTypeDecimal<ToDataType>)
                                vec_to[i] = convertToDecimal<FromDataType, ToDataType>(vec_from[i], vec_to.getScale());
                            else
                                throw Exception("Unsupported data type in conversion function", ErrorCodes::CANNOT_CONVERT_TYPE);
                        }
                    }
                    else
                    {
                        
                        if constexpr (std::is_floating_point_v<FromFieldType> && !std::is_floating_point_v<ToFieldType>)