Merging attribute and geometric features in QGIS?

If I understand your question right you can use the 'Dissolve Tool' in 'Geoporcessing Tools' in QGIS.

"Bayelsa Wards" would be your 'Input vector layer' and "Ward code" the 'Dissolve field'.

You can use the Singleparts to Multiparts in the Vector Geometry tools section of the processing toolbox to do this. It will prompt you for the input layer (from a dropdown list) and the Unique ID field (Ward Code) and you can specify an output file name.