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}
```
FromDateTime64Transform(UInt32 scale)
        : scale_multiplier(DecimalUtils::scaleMultiplier<DateTime64::NativeType>(scale))
    {}
    inline auto execute(DateTime64::NativeType dt, const DateLUTImpl & time_zone) const
    {
        const auto c = DecimalUtils::splitWithScaleMultiplier(DateTime64(dt), scale_multiplier);
        return Transform::execute(static_cast<UInt32>(c.whole), time_zone);
    }
};
/** Conversion of DateTime64 to Date or DateTime: discards fractional part.
 */
template <typename Name> struct ConvertImpl<DataTypeDateTime64, DataTypeDate, Name, ConvertDefaultBehaviorTag>
    : DateTimeTransformImpl<DataTypeDateTime64, DataTypeDate, TransformDateTime64<ToDateImpl>> {};
template <typename Name> struct ConvertImpl<DataTypeDateTime64, DataTypeDateTime, Name, ConvertDefaultBehaviorTag>
    : DateTimeTransformImpl<DataTypeDateTime64, DataTypeDateTime, TransformDateTime64<ToDateTimeImpl>> {};
struct ToDateTime64Transform
{
    static constexpr auto name = "toDateTime64";
    const DateTime64::NativeType scale_multiplier = 1;
    ToDateTime64Transform(UInt32 scale = 0)
        : scale_multiplier(DecimalUtils::scaleMultiplier<DateTime64::NativeType>(scale))
    {}
    inline DateTime64::NativeType execute(UInt16 d, const DateLUTImpl & time_zone) const
    {
        const auto dt = ToDateTimeImpl::execute(d, time_zone);
        return execute(dt, time_zone);
    }
    inline DateTime64::NativeType execute(UInt32 dt, const DateLUTImpl & ) const
    {
        return DecimalUtils::decimalFromComponentsWithMultiplier<DateTime64>(dt, 0, scale_multiplier);