SQL Exception handy helpers

Examples.cs

// Here are some example usages for unimportant jobs we have where crap happens occasionally:

/// <summary>
/// intended for database commands that might deadlock, but are just "nice to haves"; we don't care if they deadlock every now and then 
/// and we DON'T want them to block execution of the rest of /daily or /hourly! this returns -1 if deadlocked, otherwise, returns 
/// the # of rows that the SQL command affected
/// </summary>
private int ExecuteIgnoreDeadlocks(string sql, object param = null, bool logDeadlock = false)
{
    try
    {
        return DB.Execute(sql, param);
    }
    catch (SqlException sex) when (sex.Is(SqlErrorCode.TransactionDeadlocked_1205))
    {
        // don't care, this will be run every hour, so SOME of them will succeed
        // ...but we may care!
        if(logDeadlock) Current.LogException(sex);
        return -1;
    }
}

/// <summary>
/// The equivalent of ExecuteIgnoreDeadlocks, except it returns rows.
/// 
/// In the event of a deadlock, it returns null.
/// </summary>
private List<dynamic> QueryIgnoreDeadlocks(string sql)
{
    try
    {
        return DB.Query(sql);
    }
    catch (SqlException sex) when (sex.Is(SqlErrorCode.TransactionDeadlocked_1205))
    {
        // don't care, this will be run every hour, so SOME of them will succeed
        return null;
    }
}

ExtensionMethods.Exceptions.cs

using System;
using System.Data.SqlClient;

namespace StackOverflow
{
    static partial class ExtensionMethods
    {
        public static bool IsSqlError(this Exception ex, SqlErrorCode errorCode)
        {
            var sqlEx = ex as SqlException;
            return Is(sqlEx, errorCode);
        }

        public static bool Is(this SqlException ex, SqlErrorCode errorCode)
        {
            return ex != null && ex.Number == (int)errorCode;
        }
    }

    public enum SqlErrorCode
    {
        /// <summary>
        /// Usually FK constraint violations
        /// </summary>
        /// <remarks>
        /// Here are all native sql server errors that are a part of the SQLSTATE (ODBC) 23000 constraint error code:
        /// 
        /// select  *
        /// from    sysmessages
        /// where   error in ( 233, 272, 273, 515, 530, 547, 1505, 1508, 2601, 2615, 2626, 2627, 3604, 3605 )
        /// and msglangid = 1033
        /// </remarks>
        
        // ReSharper disable InconsistentNaming
        ConstraintViolation_547 = 547,
        DatabaseReadOnly_3906 = 3906,
        InsertNullIntoNotNull_515 = 515,
        TransactionDeadlocked_1205 = 1205,
        UniqueConstraintViolaton_2627 = 2627,
        UniqueIndexViolation_2601 = 2601,
    }
}