CASE WHEN EXISTS(SELECT 1 FROM Transactions WHERE Hash='VLEYCBLTDGGLHVQEWWIQ' AND Time=1531739096)
    THEN UPDATE Transactions SET BlockID=0, PoolHeight=NULL WHERE Hash='VLEYCBLTDGGLHVQEWWIQ' AND Time=1531739096
    ELSE INSERT INTO Transactions (Hash, Time, _From, Signature, Mode, BlockID, OutputValue, PoolHeight) VALUES('VLEYCBLTDGGLHVQEWWIQ',1531739096,'GENESIS','GENESIS',-1,0,0,NULL)
END;

System.Data.SQLite.SQLiteException: 'SQL logic error near "CASE": syntax error'