I think I found the source of problem. It looks like a bug, if some one would confirm, that would be great.

Here is what the generated Java code looks like(I am pasting only those lines that matter w.r.t to the current context):
          public void tFor_1Process() throws TalendException {
        try {
                         globalMap.put("tFor_1_CURRENT_ITERATION", 0);
            while (((Integer) globalMap.get("tFor_1_CURRENT_ITERATION")) <= 100) {     //The iteratiion for iFor component. This is where all the logic for a given iteration resides.
                               globalMap.put("tFor_1_CURRENT_ITERATION", ((Integer) globalMap.get("tFor_1_CURRENT_ITERATION")) + 20);
            }
            tDenormalize_1_DenormalizeInProcess();//This should be within the above for loop, but is outside the loop.
        } catch (Exception e) {
            throw new TalendException(this, e, currentComponent);
        }
    }
   
   //The actual code should be as follows:
    public void tFor_1Process() throws TalendException {
        try {
                         globalMap.put("tFor_1_CURRENT_ITERATION", 0);
            while (((Integer) globalMap.get("tFor_1_CURRENT_ITERATION")) <= 100) {     //The iteratiion for iFor component. This is where all the logic for a given iteration resides.
                                tDenormalize_1_DenormalizeInProcess();//This should be within the above for loop, but is outside the loop.
                               globalMap.put("tFor_1_CURRENT_ITERATION", ((Integer) globalMap.get("tFor_1_CURRENT_ITERATION")) + 20);
            }
        } catch (Exception e) {
            throw new TalendException(this, e, currentComponent);
        }
    }

Please let me know if I am doing something wrong.

Hello,

tMysqlInput the sql is "select id,name,ssn,addr1,addr2 from emp limit "+(Integer)globalMap.get(tFor_CURRENT_ITERATION)+"20";

Are you not missing a comma in +",20" ?

Hello

There is a 'Append' option on the basic setting panel of output component, if you don't select this option, the last iteration data will cover the previous data. or, you can use tUnite component between tMysqlInput and tDenormalize to merge all the data.

Best regards

        shong