Update Table

Hello All,

I have a RunBaseBatch class where I am calling a  table ABC and inserting a record.

till here everything is working fine but now I want to update a record in this table

any idea how to do it???

I am trying this following code snippet 

           if(value1 == table_needs_to_be _updated.Value1 &&

           value2 == table_needs_to_be _updated.Value2)

        {

            ttsBegin;

            table_needs_to_be _updated.selectForUpdate(true);

            table_needs_to_be _updated.Value1=  someValue;

             semesterCost.update();

            ttsCommit;

            info("Same Records cannot be Inserted"); ///  if same record is inserted again.

}

Please advice