Here I discuss how can we query a form by giving certain query condition like
- Display only records where a particular column is null
- Display only records where column is greater than or less than a certain value
- Display only records where data is in certain range of value etc etc....

Press Function Key F11 to enter into query mode and Ctrl+F11 to run the query. Hash(#) is the magic key here

Below are few examples with screenshots. As an example I have taken the FND_MESSAGE form which is available in the Application Developer responsibility. Navigation Application Developer-->Application-->Message

Condition1: Display all records where Number is NULL
Query

Result


Condition2: Display all records where Number is not null
Query

Result
Condition3: Display all records where Number is greater than 1905
Query
Result
Condition4: Display all records where Number is between 1905 and 1911
Query
Result
Condition5: Display all records where Number in 1905,1911
Query
Result

source:http://sureshvaishya.blogspot.jp/2008/02/tips-to-query-oracle-apps-forms.html