```
$ 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.
readDoubleQuoted(T & x, ReadBuffer & buf) { readText(x, buf); }
inline void readDoubleQuoted(String & x, ReadBuffer & buf) { readDoubleQuotedString(x, buf); }
inline void readDoubleQuoted(LocalDate & x, ReadBuffer & buf)
{
    assertChar('"', buf);
    readDateText(x, buf);
    assertChar('"', buf);
}
inline void readDoubleQuoted(LocalDateTime & x, ReadBuffer & buf)
{
    assertChar('"', buf);
    readDateTimeText(x, buf);
    assertChar('"', buf);
}
template <typename T>
inline void readCSVSimple(T & x, ReadBuffer & buf)
{
    if (buf.eof())
        throwReadAfterEOF();
    char maybe_quote = *buf.position();
    if (maybe_quote == '\'' || maybe_quote == '\"')
        ++buf.position();
    readText(x, buf);
    if (maybe_quote == '\'' || maybe_quote == '\"')
        assertChar(maybe_quote, buf);
}
template <typename T>
inline std::enable_if_t<is_arithmetic_v<T>, void>