Hi All,
 
Can anyone please help on the below approach?

Requirement - There is a custom object with 2 fields - Categories, Areas and both fields are of Long text area datatype. Both the fields stores comma separated values same like below:
 
Table structure records in those fields are like below:
 
ID       |      Categories               |    Areas
Rec1        C1, C2, C3, C4...               A1, A2, A3, A4...
Rec2        C2, C3, C7, C8                  A4, A5, A6, A9
 
Requirement is if user is trying to key new selections with combinations of category and area which already exists in above table then it should show validation.
 
Example - If user is trying to key C2, C4, C7, C8 and Area A3, A4, A6 then it should give an error message. 
Validation will be checking the combinations using the selections made during keying:
C2-A3, C2-A4, C2-A6
C4-A3, C4-A4, C4-A6
C7-A3, C7-A4, C7-A6
C8-A3, C8-A4, C8-A6
Above combinations needs to be validated with the table records combinations same format.
Solution Approach:
1. Implement static methods to do Salesforce SOQL query to get all the records first.
Define Static set and map variables. Set variable will be to define the combinations and Map will be if we want to have the record along.
2. Implement the below method to collect the values from comma separated to set list.
  
    public static Set<String> storeValuesInSet(String fieldValue){
        Set<String> value_lst = new Set<String>();
        //split the values and put them in a set.
        String[] values = fieldValue.split(',');
        for (Integer x = 0; x < values.size(); x++){
             value_lst.add(String.valueOf(values[x]));
         }
        return value_lst;
    }
3. The values will be stored during for loops. One for loop will be to iterate through the object records. Since fields are long text area and value is comma separated, inside first for loop will call the method storeValuesInSet and then iteratinfg
Set<String> uniqueKeys = new Set<String>();
Below will be map values:
Rec 1, Set< C1-A1, C1-A2, C1-A3, C1-A4 >
Rec 1, Set< C2-A1, C2-A2, C2-A3, C2-A4 >
Rec 1, Set< C3-A1, C3-A2, C3-A3, C3-A4 >
Rec 1, Set< C4-A1, C4-A2, C4-A3, C4-A4 >
Rec 2, Set< C2-A4, C2-A5, C2-A6, C2-A9 >
Rec 2, Set< C3-A4, C3-A5, C3-A6, C3-A9 >
Rec 2, Set< C7-A4, C7-A5, C7-A6, C7-A9 >
Rec 2, Set< C8-A4, C8-A5, C8-A6, C8-A9 >
2. Once user clicked save button, we can use contains method of set variable to find duplicates.
 
Please let me know if there is any other good way for achieving this or whether the above is correct approach?.Thanks for your help. 
 
Thanks & Regards,
Priyanka