```
$ 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.
{
    while (!buf.eof())
    {
        char * next_pos = find_first_symbols<'\t', '\n', '\\'>(buf.position(), buf.buffer().end());
        appendToStringOrVector(s, buf, next_pos);
        buf.position() = next_pos;
        if (!buf.hasPendingData())
            continue;
        if (*buf.position() == '\t' || *buf.position() == '\n')
            return;
        if (*buf.position() == '\\')
            parseComplexEscapeSequence(s, buf);
    }
}
void readEscapedString(String & s, ReadBuffer & buf)
{
    s.clear();
    readEscapedStringInto(s, buf);
}
template void readEscapedStringInto<PaddedPODArray<UInt8>>(PaddedPODArray<UInt8> & s, ReadBuffer & buf);
template void readEscapedStringInto<NullOutput>(NullOutput & s, ReadBuffer & buf);
/** If enable_sql_style_quoting == true,
  *  strings like 'abc''def' will be parsed as abc'def.
  * Please note, that even with SQL style quoting enabled,
  *  backslash escape sequences are also parsed,
  *  that could be slightly confusing.
  */
template <char quote, bool enable_sql_style_quoting, typename Vector>
static void readAnyQuotedStringInto(Vector & s, ReadBuffer & buf)