可以从 Dapper DynamicParameters 获取 DbType 吗？

Question

I need iterate through Dapper DynamicParameters . So, I check this answer to get value of parameter.

foreach (var paramName in parameters.ParameterNames)
{
    var value = ((SqlMapper.IParameterLookup)parameters)[paramName];
}

Now, I need parameter DbType. Is it possible to get this information?

Answer 1

I dont know if Dapper provides a better solution for this or not, but thanks to reflection, there is nothing impossible!

var t = parameters.GetType().GetField("parameters", BindingFlags.NonPublic | BindingFlags.Instance);

if (t != null) 
{  
     foreach (DictionaryEntry dictionaryEntry in (IDictionary)t.GetValue(parameters))
     {
        var dbType = (DbType)dictionaryEntry.Value?.GetType().GetProperty("DbType")?.GetValue(dictionaryEntry.Value);  
     }
}

Answer 2

You can do this! Please check the code below:

 private List<DbType> GetParameterType<T>()
    {
        var type = typeof(T);
        var properties = type.GetProperties().Select(property => property.PropertyType.Name).ToList();

        var dbTypes = new List<DbType>();
        foreach (var prop in properties)
        {
            var tryParse = Enum.TryParse<DbType>(prop, out var result);
            if (tryParse)
                dbTypes.Add(result);
        }

        return dbTypes;
    }

And then, the call of this is simple: var dbTypes = GetParameterType<T>(); where T is your object