```
$ 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.
{
    return checkStringByFirstCharacterAndAssertTheRest(s.c_str(), buf);
}
inline bool checkStringByFirstCharacterAndAssertTheRestCaseInsensitive(const String & s, ReadBuffer & buf)
{
    return checkStringByFirstCharacterAndAssertTheRestCaseInsensitive(s.c_str(), buf);
}
inline void readBoolText(bool & x, ReadBuffer & buf)
{
    char tmp = '0';
    readChar(tmp, buf);
    x = tmp != '0';
}
inline void readBoolTextWord(bool & x, ReadBuffer & buf)
{
    if (buf.eof())
        throwReadAfterEOF();
    if (*buf.position() == 't')
    {
        assertString("true", buf);
        x = true;
    }
    else
    {
        assertString("false", buf);
        x = false;
    }
}
enum class ReadIntTextCheckOverflow