Hi,Feature not supported: table variable cannot be compared: FIDCOUNT

I have a procedure for calculating a new column in tables.I want to use  loop for number of columns repeating with same values.

So I just tried with one variable to store  count of columns and then i used that table type count variable as a conditional variable in while loop.Now i got the error

Feature not supported: table variable cannot be compared.

Can anyone help me to resolve the error.

FIDCOUNT=select count(distinct FAMILY_ID) from family;

WHILE :outloop_count<:FIDCOUNT DO

//query

outloop_count:=:outloop_count+1;

END WHILE;