Question about functions

I was send an example for a function definition created with ecpg:

EXEC SQL INCLUDE sqlca;

int my_fun (void){EXEC SQL BEGIN DECLARE SECTION;int            sql_index = 0;EXEC SQL END DECLARE SECTION;    
EXEC SQL WHENEVER SQLERROR GOTO Error;EXEC SQL SELECT MIN(index) INTO :sql_index FROM tab;
return (sql_index);

Error:return (sqlca.sqlcode);    }

I have never tried this so I wonder if this is possible. Any comments?

Anyway it does not seem to work as it should. I did create a mini table to
test it:

mm=> select * from tab;
index
-----  14   7
(2 rows)
mm=> select my_fun();
my_fun
------ -220
(1 row)

Now -220 certainly is not the minimum of 14 and 7. So what did I do wrong
here?

Michael
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