How to query a dictionary by another dictionary in C#

    public class MyFiles
    {
        public int Id { get; set; }
        public string FileName { get; set; }

        public IDictionary<string, string> Metadata { get; set; } = new Dictionary<string, string>();
    }

        private void button1_Click(object sender, EventArgs e)
        {
            var list = new List<MyFiles>();

            list.Add(new MyFiles
            {
                Id = 1,
                FileName = "myTestfile.jpg",
                Metadata = new Dictionary<string, string>
                {
                    { "FileSize", "599" },
                    { "GroupId", "25" },
                    { "TypeId", "Finance" },

                }
            });

            list.Add(new MyFiles
            {
                Id = 2,
                FileName = "myTestfile1.jpg",
                Metadata = new Dictionary<string, string>
                {
                    { "FileSize", "748" },
                    { "GroupId", "25" },
                    { "TypeId", "HR" },

                }
            });

            list.Add(new MyFiles
            {
                Id = 3,
                FileName = "myTestfile23.jpg",
                Metadata = new Dictionary<string, string>
                {
                    { "FileSize", "718" },
                    { "GroupId", "78" },
                    { "TypeId", "IT" },

                }
            });

            list.Add(new MyFiles
            {
                Id = 4,
                FileName = "myTestfile2.jpg",
                Metadata = new Dictionary<string, string>
                {
                    { "FileSize", "783" },
                    { "GroupId", "78" },
                    { "TypeId", "IT" },

                }
            });


            // Instance one
            var queryDictionary = new Dictionary<string, string>();

            queryDictionary.Add("GroupId", "78");
            queryDictionary.Add("TypeId", "IT");

            // Expected results would be Ids: 3 and 4

            // Instance two
            queryDictionary.Clear();

            queryDictionary.Add("GroupId", "78");
            queryDictionary.Add("FileSize", "783");

            // Expected results would be Ids: 4

        }

        public IEnumerable<AzureStorageFileDownloadResultDTO> GetFiles(IDictionary<string, string> metadata, BlobContainerClientDTO blobContainerClient)
        {

        }

Directly above is what I would like it to be, but I can't figure out how to query it properly.

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tvb2727

Participant

1038 Points

2816 Posts

Re: How to query a dictionary by another dictionary in C#

Jan 18, 2021 04:07 PM|tvb2727|LINK

Here is the initial code.

Here I'm only checking one key value pair where I need to check a dictionary of metadata <string, string>():

        public IEnumerable<AzureStorageFileDownloadResultDTO> GetFiles(ModuleType moduleType, string metadataKey, string metadataValue, BlobContainerClientDTO blobContainerClient)
        {
            if (blobContainerClient == null)
            {
                throw new ArgumentNullException(nameof(blobContainerClient));
            }

            if (string.IsNullOrWhiteSpace(blobContainerClient.ConnectionString) == true)
            {
                throw new PropertyNullOrWhiteSpaceException(nameof(blobContainerClient.ConnectionString));
            }

            if (string.IsNullOrWhiteSpace(blobContainerClient.ContainerName) == true)
            {
                throw new PropertyNullOrWhiteSpaceException(nameof(blobContainerClient.ContainerName));
            }

            if (moduleType == ModuleType.None)
            {
                throw new ArgumentNullException(nameof(moduleType));
            }

            if (string.IsNullOrWhiteSpace(metadataKey) == true)
            {
                throw new ArgumentOutOfRangeException(nameof(metadataKey));
            }

            if (string.IsNullOrWhiteSpace(metadataKey) == true)
            {
                throw new PropertyNullOrWhiteSpaceException(nameof(metadataKey));
            }

            if (string.IsNullOrWhiteSpace(metadataValue) == true)
            {
                throw new PropertyNullOrWhiteSpaceException(nameof(metadataValue));
            }

            BlobContainerClient container = GetBlobContainerForDownloads(blobContainerClient);

            var blobItems = GetAllBlobsForContainer(container);

            if (blobItems == null)
            {
                return Enumerable.Empty<AzureStorageFileDownloadResultDTO>();
            }

            IList<AzureStorageFileDownloadResultDTO> results = new List<AzureStorageFileDownloadResultDTO>();

            AzureStorageFileDownloadResultDTO result;

            // pull all blob items within the container where there is a meta data match for the file manager module type AND the meta data key and value passed in AND there is not a value of IsFileDeleted as "true"
            foreach (var item in blobItems.Where(w => w.Metadata.Contains(new KeyValuePair<string, string>(FileManagerMetadataContants.ModuleType, moduleType.ToString())) == true && w.Metadata.Contains(new KeyValuePair<string, string>(metadataKey, metadataValue)) == true && w.Metadata.Contains(new KeyValuePair<string, string>(FileManagerMetadataContants.IsFileDeleted, FileManagerMetadataContants.IsFileDeletedValue)) == false))
            {
                result = new AzureStorageFileDownloadResultDTO()
                {
                    FileData = null, // do not pull the file data when returning all the files ; the developer will return back to the API to get the actual file with the blob name
                    FileFound = true,
                    BlobName = item.Name,
                    FileName = GetFileName(item.Metadata),
                    FileNameWithExtension = GetFileNameWithExtension(item.Metadata),
                    ContentType = item.Properties.ContentType,
                    FileExtension = item.Properties.ContentType,
                    Metadata = item.Metadata
                };

                results.Add(result);
            }

            return results;
        }

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tvb2727

Participant

1038 Points

2816 Posts

Re: How to query a dictionary by another dictionary in C#

Jan 18, 2021 04:23 PM|tvb2727|LINK

Here is what the error looks like when I try to just do .Contains() on the metadata:

Error CS1503 Argument 1: cannot convert from 'System.Collections.Generic.IDictionary<string, string>' to 'System.Collections.Generic.KeyValuePair<string, string>'

https://imgur.com/a/BMdRXLf

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tvb2727

Participant

1038 Points

2816 Posts

Re: How to query a dictionary by another dictionary in C#

Jan 18, 2021 08:51 PM|tvb2727|LINK

mgebhard

Shared sample data, code, and expected results.

I've tried this, but it isn't working. It will remove the blob item with a meta data custom item as IsFileDeleted as true and IsFileDeletedValue was true, but does not removed the blobItem with a ModuleId as 3, as I am passing in for the ModuleId item to be 5.

            foreach (var item in blobItems.Where(w => w.Metadata.Any(a => (metadata.Select(s => s.Key).Contains(a.Key) == true
                                                                       && metadata.Select(s => s.Value).Contains(a.Value) == true)
                                                                       && (metadata.Select(s => s.Key).Contains(FileManagerMetadataContants.IsFileDeleted) == false
                                                                       && metadata.Select(s => s.Key).Contains(FileManagerMetadataContants.IsFileDeletedValue) == false)) == true))
            {
                var newFileItem = new FileItemDTO
                {
                    Id = item.Name,
                    FileId = GetMetadataValue(item.Metadata, FileManagerMetadataContants.FileId),
                    FileName = GetMetadataValue(item.Metadata, FileManagerMetadataContants.FileName),
                    FileNameWithExtension = GetMetadataValue(item.Metadata, FileManagerMetadataContants.FileNameWithExtension),
                    FileExtension = GetMetadataValue(item.Metadata, FileManagerMetadataContants.FileExtension),
                    FileSize = item.Properties.ContentLength ?? 0,
                    ModuleId = GetMetadataValue(item.Metadata, FileManagerMetadataContants.ModuleId),
                    EndItemId = GetMetadataValue(item.Metadata, FileManagerMetadataContants.EndItemId),
                    EndItemTypeId = GetMetadataValue(item.Metadata, FileManagerMetadataContants.EndItemTypeId),
                    MetadataDictionary = item.Metadata,
                };

                // Convert the metadata dictionary into a IList<MetadataDTO> so that the developer can query against it easier compared to querying against a dictionary
                foreach (var itemMetadataJson in newFileItem.MetadataDictionary)
                {
                    newFileItem.Metadata.Add(new MetadataDTO { Key = itemMetadataJson.Key, Value = itemMetadataJson.Value });
                }

                fileItems.Add(newFileItem);
            }

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mbanavige

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Re: How to query a dictionary by another dictionary in C#

Jan 18, 2021 08:53 PM|mbanavige|LINK

I think i would approach this by looking for the Intersect of the 2 disctionaries.

https://stackoverflow.com/questions/10685142/c-sharp-dictionaries-intersect

Mike Banavige

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tvb2727

Participant

1038 Points

2816 Posts

Re: How to query a dictionary by another dictionary in C#

Jan 18, 2021 09:22 PM|tvb2727|LINK

mbanavige

I think i would approach this by looking for the Intersect of the 2 disctionaries.

https://stackoverflow.com/questions/10685142/c-sharp-dictionaries-intersect

This is just checking the key though. I need to check the Key and the Value to make sure they match?

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tvb2727

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1038 Points

2816 Posts

Re: How to query a dictionary by another dictionary in C#

Jan 18, 2021 09:29 PM|tvb2727|LINK

mbanavige

I think i would approach this by looking for the Intersect of the 2 disctionaries.

https://stackoverflow.com/questions/10685142/c-sharp-dictionaries-intersect

Mine are set as IDictionary, I think they need to be Dictionary before the .ContainsValue is available.

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PaulTheSmith

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927 Posts

Re: How to query a dictionary by another dictionary in C#

Jan 18, 2021 10:39 PM|PaulTheSmith|LINK

I would create a little method since the logic is complex

IEnumerable<MyFiles> MatchOnQuery(
                            IDictionary<string, string> query, 
                            IList<MyFiles> files)
{
   return files
            .Where(f => query
                           .All(q => f.Metadata.ContainsKey(q.Key) &&
                                     f.Metadata[q.Key] == q.Value)
                  );
}

Calling MatchOnQuery(queryDictionary, list) returns you the matching MyFiles

(BTW - personal bugbear of mine, MtFiles seems to model a single thing - a file. Give it a singular name - MyFile. It really makes a big difference when you are thinking about the logic and playing with possible code to have singular names for single things and plural names for plural things.)

(BTW-2 - Thanks for the succinct sample, data and expectations. It would be great if more questions were presented like you have done. Having a sample which can be executed with known results makes it so much easier for people to help)

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tvb2727

Participant

1038 Points

2816 Posts

Re: How to query a dictionary by another dictionary in C#

Jan 19, 2021 02:41 PM|tvb2727|LINK

PaulTheSmith

I would create a little method since the logic is complex
IEnumerable<MyFiles> MatchOnQuery(
                            IDictionary<string, string> query, 
                            IList<MyFiles> files)
{
   return files
            .Where(f => query
                           .All(q => f.Metadata.ContainsKey(q.Key) &&
                                     f.Metadata[q.Key] == q.Value)
                  );
}
Calling MatchOnQuery(queryDictionary, list) returns you the matching MyFiles

(BTW - personal bugbear of mine, MtFiles seems to model a single thing - a file. Give it a singular name - MyFile. It really makes a big difference when you are thinking about the logic and playing with possible code to have singular names for single things and plural names for plural things.)

(BTW-2 - Thanks for the succinct sample, data and expectations. It would be great if more questions were presented like you have done. Having a sample which can be executed with known results makes it so much easier for people to help)

Thanks PaulTheSmith!

This is close to what I ended up doing.

Here is mine:

            // only pull blobItems with metadata that match AND that are not deleted.
            blobItems = blobItems.Where(
                mf => metadata.All(
                    kvp => mf.Metadata.TryGetValue(kvp.Key, out var outMetadata) && outMetadata == kvp.Value
                           && (mf.Metadata.TryGetValue(FileManagerMetadataContants.IsFileDeleted, out var outIsFileDelete) && outIsFileDelete == FileManagerMetadataContants.IsFileDeletedValue) == false));

Other *possible items: c# - How to query a nested object dictionary against another dictionary key/values matching - Stack Overflow

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