```
$ 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.
if (decoded_char != '\\'
            && decoded_char != '\''
            && decoded_char != '"'
            && decoded_char != '`'  
            && decoded_char != '/'  
            && decoded_char != '='  
            && !isControlASCII(decoded_char))
        {
            s.push_back('\\');
        }
        s.push_back(decoded_char);
        ++buf.position();
    }
}
template <typename Vector, typename ReturnType>
static ReturnType parseJSONEscapeSequence(Vector & s, ReadBuffer & buf)
{
    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 Exception(message, code);
        return ReturnType(false);
    };
    ++buf.position();
    if (buf.eof())
        return error("Cannot parse escape sequence", ErrorCodes::CANNOT_PARSE_ESCAPE_SEQUENCE);