res=sql_ask_database(conn,f"""SELECT chain_id from chain WHERE structure_id='{pdb_id}' AND chain_name='{pdb_chain_id}' AND rfam_acc IS NULL AND issue=0""")
ifnotlen(res):# the chain is NOT yet in the database, or this is a known issue
pd.read_sql_query("SELECT rfam_acc, description, idty_percent, nb_homologs, nb_3d_chains, nb_total_homol, max_len, comput_time, comput_peak_mem from family ORDER BY nb_3d_chains DESC;",
res=sql_ask_database(conn,f"""SELECT chain_id from chain WHERE structure_id='{pdb_id}' AND chain_name='{pdb_chain_id}' AND rfam_acc='{rfam}' AND issue=0""")
ifnotlen(res):# the chain is NOT yet in the database, or this is a known issue