Concat the value of column col of all rows of resultset. Return a string with values delimited with comma char.

• Supose that was load a result as follow:

  %MyXQL.Result{
  columns: ["id", "name", "email", "age", "address"],
  connection_id: 1515,
  last_insert_id: 0,
  num_rows: 1,
  num_warnings: 0,
  rows: [
    [1,"Johannes Backend","johannes@backend.com",54,"404 street"],
    [2,"Peter Druggking","peter@thedrugger.com",23,"404 street"],
    [3,"Josephine Frontfull","josephine@staline.com",34,"404 street"]
  ]
  }

iex > Krug.ResultSetHandler.concat_cols_of_result_rows(resultset,0)
"1,2,3"

iex > Krug.ResultSetHandler.concat_cols_of_result_rows(resultset,1)
"Johannes Backend,Peter Druggking,Josephine Frontfull"

iex > Krug.ResultSetHandler.concat_cols_of_result_rows(resultset,2)
"johannes@backend.com,peter@thedrugger.com,josephine@staline.com"

iex > Krug.ResultSetHandler.concat_cols_of_result_rows(resultset,3)
"54,23,34"

Obtain the value of a column col of a row row of resultset.

Return a empty string if value is nil.

You could use "skip_verification" parameter as true, if you are sure that values already were verified, this will improve performance.

• Supose that was load a result as follow:

  %MyXQL.Result{
  columns: ["id", "name", "email", "age", "popularitypercent", "address"],
  connection_id: 1515,
  last_insert_id: 0,
  num_rows: 1,
  num_warnings: 0,
  rows: [
    [1,"Johannes Backend","johannes@backend.com",54,95.7,"404 street"],
    [2,"Peter Druggking","peter@thedrugger.com",23,66.6,"404 street"],
    [3,"Josephine Frontfull","josephine@staline.com",34,17.3,"404 street"]
  ]
  }

And you want transform it to a pretty map array as [%{},%{},%{}], then you could iterate recursively the resultset, making some as this for each row:

%{
  id: Krug.ResultSetHandler.get_column_value(resultset,row,0) |> Krug.NumberUtil.to_integer(),
  name: Krug.ResultSetHandler.get_column_value(resultset,row,1),
  email: Krug.ResultSetHandler.get_column_value(resultset,row,2),
  age: Krug.ResultSetHandler.get_column_value(resultset,row,3) |> Krug.NumberUtil.to_integer(),
  popularitypercent: Krug.ResultSetHandler.get_column_value(resultset,row,4) |> Krug.NumberUtil.to_float(),
  address: Krug.ResultSetHandler.get_column_value(resultset,row,5)
}