how to save array of values in CDT in process model

Did you check about the Multiple checkbox is checked for the data input you would have created?

yes

when you have arrays of value(CDT) and you want to write all to rows in database then you have to config this in "write to data store entity node"  below name and type there is a checkbox multiple(for your data input) , try to select it and then try writing to the data store entity

Multiple checkbox is greyed out




for more clarity, Im pasting the script task where im passing the array values to cdt,

You should first cast this data to your CDT.

Check this out:

a!localVariables(
  local!data:{
    name : {"a","b","c","d"},

    age : {1,2,3,4},

    email : {"@e","@r","@t","@w"}
  },
  a!forEach(
    items: local!data.name,
    expression: type!<<cdt_name>>(
      name: fv!item,
      age: index(local!data.age,fv!index,{}),
      email:index(local!data.email,fv!index,{})
    )
  )
)

This is not the most appropriate way, But it will work.

you are writing the data (param3) right? were you able to store multiple data in it ? from your process instance photo it shows only one set of data(first values).

if thats the case then - 
check if you variable param3 can have multiple values

and try storing the data into the variable like this 

a!localVariables(
  local!name:{1,2,3,4},
  local!age:{"10","20","30","40"},
  local!param3:  a!forEach(
    items:local!name,
    expression:'type!{urn:com:appian:types:CP}CP_uiDataBase'(
      test_int: local!name[fv!index],
      test_text: local!age[fv!index],
      test_date: null
    ) 
  ),
  local!param3
)

It is not performant or considered best practice to have a single field contain an array of items. I would recommend you go back to your initial interface and update the rule input to be an array. Check out this pattern on Appian Documentation https://docs.appian.com/suite/help/22.4/recipe-add-edit-and-remove-data-in-an-inline-editable-grid.html and look at how local!employees (line 11) is creating a list of arrays. Once you have reviewed the pattern to see how new employees are added to the local variable, you can reconstruct your interface to allow the same behavior. Eventually, you can pass that array of items into the process where the Write to DSE node will see that each array should represent a row in the db.

Thanks it has worked