Pull all items from a Map at one time

.NET SDK
1

I am new to Couchbase and trying to determine how I might do something. We are planning on using Bucket.AddMap to keep a dictionary of items in memory for fast retrieval and we want to dictionary functionality to ensure that only one item with a particular key gets added.

We want to be able to get all of the records in a c# dictionary returned instead of only being able to access on item at a time. Does anyone have any idea of how this could be done?

Thanks for your help in advance.

James

2

@jrwallace96 -

You can use the key used to store the dictionary and var result = await bucket.GetAsync<T>("yourkey"); to fetch the entire document. “T” should be a C# Dictionary<Tkey, Tvalue> you want to store the results into.

-Jeff

3

That did not work. I am adding like this:
public override bool DictionaryAdd(string key, string mapKey, object value)
{
if (string.IsNullOrWhiteSpace(key))
throw new ArgumentNullException(nameof(key), @“The key parameter must be string value with length greater than zero.”);

        if (string.IsNullOrWhiteSpace(key))
            throw new ArgumentNullException(nameof(mapKey), @"The mapKey parameter must be string value with length greater than zero.");

        if (value == null)
            throw new ArgumentNullException(nameof(value), @"The value object parameter must not be null.");

        try
        {
            IResult result;
            if (!Bucket.Exists(key))
            {
                result = Bucket.Upsert(key, "{}");
                if (!result.Success) throw new Exception();
            }

            result = Bucket.MapAdd(key, mapKey, JsonConvert.SerializeObject(value), false);

            if (result.Success) return true;
            throw result.Exception;
        }
        catch (Exception ex)
        {
            //Logger.Error("CouchbaseCacheProvider:MapAdd", ex);
            return false;
        }
    }

And I get this error when I try to pull them out using the method you gave me:
public override IDictionary<string, TValue> DictionaryGet(string key)
{
if (string.IsNullOrWhiteSpace(key))
throw new ArgumentNullException(nameof(key), @“The key parameter must be string value with length greater than zero.”);

        var resultDictionary  = new Dictionary<string, TValue>();
        try
        {
            var result= Bucket.Get<TValue>(key);
            if (!result.Success) throw result.Exception;
            return resultDictionary;
        }
        catch (Exception ex)
        {
            //Logger.Error("", ex);
            return null;
        }
    }

The message that I get when executing {“Unable to cast object of type ‘System.String’ to type ‘TestClass’.”}

4

I did find that this worked though:
public override IDictionary<string, TValue> DictionaryGet(string key)
{
if (string.IsNullOrWhiteSpace(key))
throw new ArgumentNullException(nameof(key), @“The key parameter must be string value with length greater than zero.”);

        var resultDictionary  = new Dictionary<string, TValue>();
        try
        {
            var result = Bucket.Get<TValue>(key);
            if (!result.Success) throw result.Exception;

            var jsonDict = JsonConvert.DeserializeObject<Dictionary<string, string>>(result.Value as string);

            foreach (var kvPair in jsonDict)
            {
                resultDictionary.Add(kvPair.Key, JsonConvert.DeserializeObject<TValue>(kvPair.Value));
            }

            return resultDictionary;

        }
        catch (Exception ex)
        {
            //Logger.Error("CouchbaseCacheProvider:MapGet<T>", ex);
            return null;
        }
    }
5

This should be var result = Bucket.Get<Dictionary<string, TValue>>(key);

6
Name Value Type
This is the exception when I execute.
:arrow_forward: Exception {“Unable to cast object of type ‘System.String’ to type ‘System.Collections.Generic.Dictionary`2[System.String,CouchbaseExample.Program+TestClass]’.”} System.Exception {System.InvalidCastException}