Edit Mongodb array values to only contain alphabetic characters - mongodb

Question

I am trying to edit the data in my mongodb collection after importing the data from a csv file. One of my fields contains a mixture of alphabetic and numeric characters, and I want to edit it such that it only contains alphabetic characters to make querying easier
So I want to change this:
"categories" : [
"9100005:1:factual",
"9200041:2:arts_culture_and_the_media",
"9200055:2:history"
]
Into this:
"categories" : [
"factual",
"arts culture and the media",
"history"
]
I know that using $regex I can query for certain categories, so using:
db.bbc.find( { categories: {$regex: /factual/ }} )
I get all records with "factual" as a category, but I am unsure how to use $regex to query for multiple categories and I just feel avoiding using regular expressions entirely would be easier. Does anyone know what command I would have to run to be able to do this? Thanks.

Answer 1

Try this
db.test1.find().snapshot().forEach(function (el) {
for(a in el.Category){
print(el.Category[a].replace(/[^A-Za-z]/g, ""));
el.Category[a]=el.Category[a].replace(/[^A-Za-z]/g, "");
}
db.test1.save(el);
});
Edit:
To Preserve Space Just add space in regex.
You can use this line
el.Category[a].replace(/[^A-Za-z]*$/g, "");
To Handle Underscore
el.Category[a].replace(/[^A-Za-z_]*$/g, "");