```
$ 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.
{
    DO_NOT_CHECK_OVERFLOW,
    CHECK_OVERFLOW,
};
template <typename T, typename ReturnType = void, ReadIntTextCheckOverflow check_overflow = ReadIntTextCheckOverflow::DO_NOT_CHECK_OVERFLOW>
ReturnType readIntTextImpl(T & x, ReadBuffer & buf)
{
    using UnsignedT = make_unsigned_t<T>;
    static constexpr bool throw_exception = std::is_same_v<ReturnType, void>;
    bool negative = false;
    UnsignedT res{};
    if (buf.eof())
    {
        if constexpr (throw_exception)
            throwReadAfterEOF();
        else
            return ReturnType(false);
    }
    const size_t initial_pos = buf.count();
    bool has_sign = false;
    bool has_number = false;
    while (!buf.eof())