code: @Override
      public void deleteByColumn(String schemaName, String tableName, String columnName, Object columnValue)
      {
          URI uri = null;
          HttpResponse response = null;
          try
          {
              String q = "key=" + CouchDBUtils.appendQuotes(columnValue);
              uri = new URI(CouchDBConstants.PROTOCOL, null, httpHost.getHostName(), httpHost.getPort(),
                      CouchDBConstants.URL_SEPARATOR + schemaName.toLowerCase() + CouchDBConstants.URL_SEPARATOR
                              + CouchDBConstants.DESIGN + tableName + CouchDBConstants.VIEW + columnName, q, null);
              HttpGet get = new HttpGet(uri);
              get.addHeader("Accept", "application/json");
              response = httpClient.execute(get);
  
              InputStream content = response.getEntity().getContent();
              Reader reader = new InputStreamReader(content);
  
              JsonObject json = gson.fromJson(reader, JsonObject.class);
  
              JsonElement jsonElement = json.get("rows");
  
              closeContent(response);
  
              JsonArray array = jsonElement.getAsJsonArray();
              for (JsonElement element : array)
              {
                  JsonObject jsonObject = element.getAsJsonObject().get("value").getAsJsonObject();
  
                  JsonElement pkey = jsonObject.get("_id");
  
                  onDelete(schemaName, pkey.getAsString(), response, jsonObject);
              }
          }
          catch (Exception e)
          {
              log.error("Error while deleting row by column where column name is " + columnName
                      + " and column value is {}, Caused by {}.", columnValue, e);
              throw new KunderaException(e);
          }
          finally
          {
              closeContent(response);
          }
      }
docs: /*
  (non-Javadoc)
  
  @see com.impetus.kundera.client.Client#deleteByColumn(java.lang.String,
  java.lang.String, java.lang.String, java.lang.Object)