```
$ echo '20210101,A' | clickhouse-local --input-format CSV --structure 'd Date, s String' --query "SELECT * FROM table"
Code: 27. DB::Exception: Cannot parse input: expected ',' before: '20210101,A\n': 
Row 1:
Column 0,   name: d, type: Date,   ERROR: text "20210101,A" is not like Date

: While executing ParallelParsingBlockInputFormat: While executing File. (CANNOT_PARSE_INPUT_ASSERTION_FAILED)
```

**How to solve**

Disambiguate while parsing by absense of separators between YYYY-MM-DD.
{
    static constexpr bool throw_exception = std::is_same_v<ReturnType, void>;
    auto error = [](const char * message [[maybe_unused]], int code [[maybe_unused]])
    {
        if constexpr (throw_exception)
            throw ParsingException(message, code);
        return ReturnType(false);
    };
    if (buf.eof() || *buf.position() != '"')
        return error("Cannot parse JSON string: expected opening quote", ErrorCodes::CANNOT_PARSE_QUOTED_STRING);
    ++buf.position();
    while (!buf.eof())
    {
        char * next_pos = find_first_symbols<'\\', '"'>(buf.position(), buf.buffer().end());
        appendToStringOrVector(s, buf, next_pos);
        buf.position() = next_pos;
        if (!buf.hasPendingData())
            continue;
        if (*buf.position() == '"')
        {
            ++buf.position();
            return ReturnType(true);
        }
        if (*buf.position() == '\\')
            parseJSONEscapeSequence<Vector, ReturnType>(s, buf);
    }
    return error("Cannot parse JSON string: expected closing quote", ErrorCodes::CANNOT_PARSE_QUOTED_STRING);
}
void readJSONString(String & s, ReadBuffer & buf)