Create a Trigger to genearate a random alphanumeric string in informix - informix

Question

To create a trigger before insert using Informix database.
When we try to insert a record into the table it should insert random alphanumeric string into one of the field. Are there any built in functions?
The table consists of the following fields:
empid serial NOT NULL
age int
empcode varchar(10)
and I am running
insert into employee(age) values(10);
The expected output should be something as below:
id age empcode
1, 10, asf123*
Any help is appreciated.

Answer 1

As already commented there is no existing function to create a random string however it is possible to generate random numbers and then convert these to characters. To create the random numbers you can either create a UDR wrapper to a C function such as random() or register the excompat datablade and use the dbms_random_random() function.
Here is an example of a user-defined function that uses the dbs_random_random() function to generate a string of ASCII alphanumeric characters:
create function random_string()
returning varchar(10)
define s varchar(10);
define i, n int;
let s = "";
for i = 1 to 10
let n = mod(abs(dbms_random_random()), 62);
if (n < 10)
then
let n = n + 48;
elif (n < 36)
then
let n = n + 55;
else
let n = n + 61;
end if
let s = s || chr(n);
end for
return s;
end function;
This function can then be called from an insert trigger to populate the empcode column of your table.