data1;
if(some condition1 = 1) then
read this data 2;
end if;
if (some condition2 = 0) then 
read this data 3;
read data 4;
end if;
if(some condition3 = 11) then
read this data 5;
data 6;
end if;
if (some condition2 = 0) then 
read this data 6;
end if;