Forum Discussion

mugheessiddiqui's avatar
mugheessiddiqui
Contributor
8 years ago

Read Blob object from DB and convert to System.Collection.Generic.List type of object.

I have scenario where database field stores a System.Collection.Generic.List of Double object. Now I want to read a BLOB object from database field and convert it to list of Array or any type collect...
  • tristaanogre's avatar
    tristaanogre
    8 years ago

    Rather than "Value", you might want to use the GetChunk method.  What you'll need to do is get the ActualSize of the field and then use GetChunk to retrieve it.  I've not tested this but it might look something like this:

     rs.MoveFirst();
var blobSize = rs.Fields("slices").ActualSize;
  var blob = rs.Fields("slices").GetChunk(blobSize);
tristaanogre's avatar
tristaanogre
Esteemed Contributor
8 years ago

Rather than "Value", you might want to use the GetChunk method.  What you'll need to do is get the ActualSize of the field and then use GetChunk to retrieve it.  I've not tested this but it might look something like this:

 rs.MoveFirst();
var blobSize = rs.Fields("slices").ActualSize;
  var blob = rs.Fields("slices").GetChunk(blobSize);
  • mugheessiddiqui's avatar
    mugheessiddiqui
    Contributor
    8 years ago

    Thanks Now I have gotten Blob object.

     

    Second Issue is to Cast the Blob object in some list/dictionary type object of JavaScript for traversing. As I told you we have stored blob object type of System.Collection.Generic.List of Double.

     

    I have found the following description of System.Collection.Generic.List that takes the "<CLRType> collection" object. I don't know how to define <CLRType> collection object.

     

    Description: System.Collection.Generic.List`1 zctor_3(<CLRType> collection);

     

    So far code looks like and I get type Mismatch error.

     

    rs.MoveFirst();

var blobSize = rs.Fields("slices").ActualSize;
var blob = rs.Fields("slices").GetChunk(blobSize);


var objList = Aliases.appName.AppDomain("appUI.exe").dotNET.System_Collections_Generic.List_1.zctor_3(blob); // Gives "Type Mismatch Error"

     

     

    • tristaanogre's avatar
      tristaanogre
      Esteemed Contributor
      8 years ago

      if your Blob is an image, it's not a collection.  A collection is an object that has fields and properties and items.  At least, that's my understanding.

       

      I don't know the specific collection object you are trying to use so I can't help you further.

      • mugheessiddiqui's avatar
        mugheessiddiqui
        Contributor
        8 years ago

        No Blob is not an image, it's an serialized object of System.Collections.Generic.List.

    • AlexKaras's avatar
      AlexKaras
      Champion Level 3
      8 years ago

      Hi,

       

      I am not absolutely sure, but I think that you should:

      -- Register relevant (system.dll?) .Net assembly in dotNet Bridge in TestComplete and

      -- Use something like

      var objList = dotNET.System_Collections_Generic.List_1.zctor_3(blob);

      in your code.

      As a result, objList variable should contain deserialized list of doubles that cannot be used 'as is' in your test code and must be converted to array or delimited string or something like that that can be iterated and used in JScript.

       

      • mugheessiddiqui's avatar
        mugheessiddiqui
        Contributor
        8 years ago

        System.Collection.Generic.List included in mscorlib.dll and it is already available in Test Complete.

        I think I have to deserialize the object but not sure how to do it.