bill <william@TechServSys.com> wrote in news:1191181320.074514.138890
@y42g2000hsy.googlegroups.com:

> On Sep 30, 3:35 pm, "Paul Lautman" <paul.laut...@btinternet.com>
> wrote:
>> bill wrote:
>> > I give this sql request:
>> > $sql = "SELECT * FROM incoming_email order by 'status','serial' limit
>> > 1 ";
>>
>> > where status is a 5 char varchar and serial is a mediumint and the
>> > primary key.
>>
>> > There is an index
>> > STATUS with no cardinality and fields: status, serial
>>
>> > The row returned is the one with the lower serial, but a higher status
>>
>> > eg serial status
>> > 269 held
>> > is returned instead of
>> > 270 (status is blank)
>>
>> > How should the selection be written ?
>>
>> > bill
>>
>> Is status blank or is it NULL?
>
>
> This is a good question. It is never defined in the insert, but the
> structure says that the value may not be null but no default value is
> given.
> A quick select using phpMyAdmin for status = NULL returns no records
> and one where status = '' (that is two single quotes) returns a
> record, so I presume it is blank.
>

> status = NULL
Nothing EVER "=" NULL

WHERE STATUS IS NULL might provide better/different results!