Question

We use firebird as a local testing database and most of our clients use SQL Server or Oracle.

This works in MS SQL Server, but not in Firebird. (haven’t tested it n Oracle yet)

CONVERT(char(8),MAX(p.end_Time)-MIN (p.start_Time),8) as duration

is there a way to acoomplish this same thing for (Firebird, Oracle, and MS Sql Server)?

thanks

Answer 1

For Firebird you need to use DATEDIFF to obtain a difference between two timestamps (datetimes). This BTW is similar to the SQL Server DATEDIFF. If you then want to cast it to char, you can use CAST, eg CAST(DATEDIFF(DAY, MAX(p.end_Time), MIN(p.start_Time)) AS CHAR(8)) should do the trick (or you can simply do CAST(MAX(p.end_Time) - MIN (p.start_Time) AS CHAR(8)) as timestamps are subtractable.

I just noticed though that the option you specify in your CONVERT will convert to hh:mi:ss. There is no such option in Firebird. If you need to convert specifically to hh:mi:ss, you might want to look at UDF libraries like FreeAdhocUDF (specifically F_SECONDS2PERIOD) or rFunc UDF. If all else fails, you could write your own UDF.