i have a problem when i want to use my 2nd table i see "there is no row at position 0" and when i look my projects folder i see my database's backup file and i was opened it then i cant see my 2.nd table in backup file. what should i do?

Dont forget tables start at 0 not 1, generally if your after line 1 use linenumber - 1.

It might help not fully sure of your problem. Addressing for data boxes is generally hex, so decimal to hex conversion max number is 255 ie ff so a max of 256 accessible numbers per address bit, 1 = 00, 256 = 255 or ff.

Otherwise check your database has a second table intialised to start with and your identifying it correctly. Ive made that mistake a few times myself. Always worth a quick check.