if语句的问题，我是delphi初学者。谁能帮我解释下这段话的意思？万分感谢！！！

Question

  if not QueryCopyDataFlag(sPicName) then //没拷贝
        begin
          for i:=1 to 3 do //3个表
          begin
            sSQL:='insert into  tb_Data_'+inttostr(i)+'_5 select * from  tb_Data_'+inttostr(i)+'_4'+
              ' where batchName='+Quotedstr(CurrBatchName)+' and PicName='+Quotedstr(sPicName);
            if not ExecSQLString(sSQL) then
            begin
              TDBConnector.Instance.Connection.RollbackTrans;
              Exit;
            end;
          end;
          sSQL:='update TB_Picture set Status5=1, Begin5='+ QuotedStr(DateTimeToStr(sDate))+',User5='+
          QuotedStr(TLoginUser.Instance.UserID)+' where BatchName='+QuotedStr(CurrBatchName)+'and PicName='+Quotedstr(sPicName);
          if not ExecSQLString(sSQL) then
          begin
            TDBConnector.Instance.Connection.RollbackTrans;
            Exit;
          end;
        end;
        next
      end;//end while
      Close;
    finally
      Free;
    end;
  end;

Answer 1

if not QueryCopyDataFlag(sPicName) then 
这有什么解释的如果 QueryCopyDataFlag(sPicName) 返回不为真 则执行下面的程序

Answer 2

  if not QueryCopyDataFlag(sPicName) then //没拷贝 
        begin 
          for i:=1 to 3 do //3个表 
          begin 
            sSQL:='insert into  tb_Data_'+inttostr(i)+'_5 select * from  tb_Data_'+inttostr(i)+'_4'+ 
              ' where batchName='+Quotedstr(CurrBatchName)+' and PicName='+Quotedstr(sPicName);    //插入数据
            if not ExecSQLString(sSQL) then //如果执行失败
            begin 
              TDBConnector.Instance.Connection.RollbackTrans; //回滚事务
              Exit; 
            end; 
          end; 
          sSQL:='update TB_Picture set Status5=1, Begin5='+ QuotedStr(DateTimeToStr(sDate))+',User5='+ 
          QuotedStr(TLoginUser.Instance.UserID)+' where BatchName='+QuotedStr(CurrBatchName)+'and PicName='+Quotedstr(sPicName);  //更新TB_Picture
          if not ExecSQLString(sSQL) then //如果执行不成功
          begin 
            TDBConnector.Instance.Connection.RollbackTrans; //回滚事务
            Exit; 
          end; 
        end; 
        next 
      end;//end while 
      Close; 
    finally 
      Free; 
    end; 
  end;

Answer 3

 TDBConnector.Instance.Connection.RollbackTrans; //回滚事务
              Exit; 
            end; 
          end; 
          sSQL:='update TB_Picture set Status5=1, Begin5='+ QuotedStr(DateTimeToStr(sDate))       +',User5='+ 
          QuotedStr(TLoginUser.Instance.UserID)+' where BatchName='+QuotedStr(CurrBatchName)+'and PicName='+Quotedstr(sPicName);  //更新TB_Picture
          if not ExecSQLString(sSQL) then //如果执行不成功
          begin 
            TDBConnector.Instance.Connection.RollbackTrans; //回滚事务                     
            Exit; 那怎么在回滚事物中还有个sql语句是干吗的

Answer 4

sSQL:='update TB_Picture set Status5=1, Begin5='+ QuotedStr(DateTimeToStr(sDate))+',User5='+ 
          QuotedStr(TLoginUser.Instance.UserID)+' where BatchName='+QuotedStr(CurrBatchName)+'and PicName='+Quotedstr(sPicName);  //更新TB_Picture
应该是更改状态的；第一个回滚只是 针对上一个SQL语句的处理，即'insert into  tb_Data_'+inttostr(i)+'_5 select * from  tb_Data_'+inttostr(i)+'_4'+ 
              ' where batchName='+Quotedstr(CurrBatchName)+' and PicName='+Quotedstr(sPicName);    它与后边的无关