Question:
I need some help with the DATETIME data type conversion. I have an Informix database running in a UNIX environment and I need to insert the system hour into an integer type column. I can’t find any function to convert the DATETIME value into a number type. I already have a stored procedure that does the insert with other fields. Until now, I was inserting 0 in this field, but now I need to change it.

How can I do this?

Answer:
You’re looking for the EXTEND function. If this_date is a date-time data type, the following SQL code will extract the system hour from this_date:

SELECT EXTEND(this_date, hour to hour)FROM  whatever_table);