c# - How to associate a customized number with exception -

i have code want throw 2 exceptions; however, exception same different values. know elegant generic way determine of these errors occurred.

i know can 2 try catches or can set boolean determine success of query. aware can done in 1 query; however, need able determine if company key wrong or if pa id wrong. know can create own exception , add additional field it. unfortunately, not believe of these optimal solution , has been bothering me quite time.

any information best practice appreciated.

using (var ora = new oracleconnection(data.connectionstring)) {     string sqlgetcompanyid = "select company_id companies key = :key";     string sqlvalidatedelete = "select * pa pa_id = :paid , company_id = :cid";      ora.open();     int companyid = 0;      using (var command = ora.createcommand())     {         command.commandtext = sqlgetcompanyid;         command.parameters.add(":key", oracledbtype.varchar2).value = ckey;          using (var reader = command.executereader(commandbehavior.singlerow))         {             if (reader.read())                companyid = unchecked((int)((long)reader["company_id"]));             else                throw new argumentexception("invalid company key");         }      }       using (var command = ora.createcommand())      {          command.commandtext = sqlvalidatedelete;          command.parameters.add(":cid", oracledbtype.int32).value = companyid;          command.parameters.add(":paid", oracledbtype.int32).value = paid;           using (var reader = command.executereader(commandbehavior.singlerow))          {              if (!reader.read())                 throw new argumentexception("price agreement id company not exist");              rv = unchecked((int)((long)reader["row_version"]));          }       }    } 

i'd suggest creating custom exception each:

public class invalidcompanykeyexception : argumentexception {    public invalidcompanykeyexception() : base() {}    public invalidcompanykeyexception(string message) : base(message) {}    public invalidcompanykeyexception(string message, exception inner) : base(message, inner) {} }  public class priceagreementidnotfoundexception : argumentexception {    public priceagreementidnotfoundexception() : base() {}    public priceagreementidnotfoundexception(string message) : base(message) {}    public priceagreementidnotfoundexception(string message, exception inner) : base(message, inner) {} } 

you can catch these separately, or can catch either 1 argumentexception. i've included 3 separate constructors each exception because that's microsoft recommends. recommend making exception serializable if they'll used in scenarios, example doesn't seem require serialization.