Input transaction hashes not matching transaction hashes

I parsed blockchain .dat files. I wanted to find transaction input address for a given transaction input.

For this I looked at “prev hashes” from inputs, reversed the byte order in them and then searched for the corresponding transaction. However, in most of the cases, reversed prev hash didn’t matched any transaction hash (actually about 5% of hashes matched only).

Is it possible or am I missing something here?

Sorry for the question but I am quite new to bitcoin.