The Return type for oracle

Return Type The number of rows changed, inserted, or deleted.

-1 for SELECT statements;

0 if no rows were affected, or the statement failed.

"select
t0.OVERDRAFT_TOLERANCE_DAYS, t0.NAME, t0.HOLDING_DATE, t0.valid_at, t0.INDEX_FUND, t0.ASSET_ID, t0.SAVEALLRESULTS, t0.FUND_OF_FUNDS, t0.CONTRACT_UL_SEC_CLASSES_ALL74B, t0.SHARED_TRANSACTIONS, t0.CONTRACT_COUNTERPARTIES_OTC61F, t0.SHARED_HOLDINGS, t0.CONTRACT_PUBLIC_ISSUER_UP_T7BF, t0.RULEGROUPLIST, t0.CONTRACT_EXCHANGES_ALLOWED, t0.FUND_INDEX_EXCEPTIONAL_COND4BE, t0.EXPANSION_COMPLETE, t0.FUND_CURRENCY, t0.BUFFER.MC, t0.BUFFER.MV, t0.FEEDER_FUND, t0.NAV.MC, t0.NAV.MV, t0.clsid, t0.xref, t0.BORROWING_LIMIT, t0.END_DATE, t0.CHECKGROUPLIST, t0.UMBRELLA_NAME, t0.EXPANSION_DEPTH, t0.BUSINESSCOUNTRY, t0.FUND_ID, t0.USERDEFINEDIDENT, t0.LIQUIDITY_BUFFER_SUFFICIENT, t0.OVERDRAFT_TOLERANCE_AMOUNT.MC, t0.OVERDRAFT_TOLERANCE_AMOUNT.MV, t0.guid, t0.tsid
from (TCHECKINGUNITS) t0

-- -1 row(s) affected."

-- -1 row(s) affected

why  i try to find this message, because it appear in the Devart dbmonitor,  i don't know what happend ?

so i find the return type for DbDataReaderBase Class : RecordsAffected Property (DbDataReaderBase), now i know what happend for -1.