date should not be insert be between two given date

SQL = "select * from paxR_AncillaryRevCode where AncillaryRevCode='" + objPrDCAncilloaryRevCode.AncillaryRevCode1 + "' and Convert(DateTime,'" + objPrDCAncilloaryRevCode.ValidFrom1 + "',103) between validFrom and ValidTo or convert(datetime,'" + objPrDCAncilloaryRevCode.ValidTo1 + "',103) between Validfrom and ValidTo and AncillaryRevCode='" + objPrDCAncilloaryRevCode.AncillaryRevCode1 + "' or Convert(DateTime,'" + objPrDCAncilloaryRevCode.ValidFrom1 + "',103)< convert(datetime,Validfrom,103) and convert(datetime,'" + objPrDCAncilloaryRevCode.ValidTo1 + "',103)> ValidTo and AncillaryRevCode='" + objPrDCAncilloaryRevCode.AncillaryRevCode1 + "'";