Re: Implement SQL in logical files

Hello,

sometimes, it's helpful to note down the problem at hand, or to explain it to someone. This helps in thinking.

I had another look at the LF definitions, and at the screen shot of an unrestricted (without S/O statements) LF query provided in the ZIP archive here:

https://leela.pocnet.net/~poc/sql-to-lf-examples.zip

Then I saw it: While an SQL join outputs records without a match in the opposite table (with NULL values in fields not being filled), LF join does not. If a record isn't found in the other file, nothing is output.

Next, I've been browsing through the DDS reference PDF for clues about this behavior. So, today I learned about JDFTVAL:

Use this file-level keyword in a join logical file so the system provides default values for fields when a join to a secondary file does not produce any records. JDFTVAL is valid only for join logical files.

Now I can test for default values (0 or blanks) in the corresponding fields with select/omit. Works like a charm! And still *much* faster than SQL on my low-end equipment. ;-)

Thanks to everyone who responded!

:wq! PoC