C#: How can I add a list of values into a msql WHERE IN clause : I have a list of values and want to use it in a query but how can I add each value with quotes into mysql where clause. 

    List <string> customerlist = new List<string>();
    sql =  SELECT * FROM customerlist WHERE custid IN customerlist

I am getting the error
[![enter image description here][1]][1]

I need to add quotes around them. Can you advice how I can do that please?
  [1]: https://i.stack.imgur.com/GpSAM.png