Selecting Null Values in SQL Statement

[JimReiley]

I have a field in a record that is defined as a 4 byte date in the ddf's. How do I select records that donot contain any information in the field? Are they nulls?

 

[DotNetGnat]

put this condition in the where clause of your sql statement...

WHERE yourfield IS NOT NULL

-DNG

 

[mirtheil]

Actually, it depends on your how the field is defined as well as what's actually in the field.
- When were these tables/DDFs created?
- Do they have a "True Null" byte?
- The IS NOT NULL may work unless the engine doesn't see the values as NULL.
- What do these empty dates look like in the PCC?
- What do these empty dates look like in the Function Executor (byte values)?


Mirtheil
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[JimReiley]

is null and is not null both work fine.

When the ddf's were originally created for this table, the flag 'nullable' was not checked. This morning I changed the definition to 'nullable' = y and reloaded the data into the table. I don't know if that made any difference or not.

When you look at this field in the PCC, the fields either show a date string or nothing. I havn't looked at them in the function executor.

Thanks for the help.