How to get the Distinct Values in TABLE Value set?

How to display distinct values in Oracle Apps valueset, below are possible options 

Method 1                                                              

Create the VIEW based on DISTINCT values; use the VIEW for creates the VALUESET.

Method 2

2) Write your query in such a way that it gives you a distinct value. You can make use of ROWID to meet the requirement.

  Example.      SELECT date_col
                      FROM   xx_custom_table xpr
                      WHERE  rowid = (select max(rowid) from  xx_custom_table xpr1
                                                    where xpr.date_col =xpr1.date_col)


Method 3

Paste the QUERY in TABLE field with alias name, and give the column name (with alias name).

(For an example)

Table : (SELECT DISTINCT PERIOD_NAME FROM GL_PERIODS) GL

Value : GL.PERIOD_NAME