Issue on customized numbering query for service call - OSCL

Hi,

I had created a FMS and set to auto generate when user select the customer code in OSCL.

However, there will be an issue when two OSCL were open at the same time, it will generate the same numbering but when saved, it will be duplicate numbering and skip one of the numbering.

For example:

Open status

OSCL one - numbering ABC0001

OSCL two - numbering ABC0001

Saved (Duplicate numbering)

OSCL one - numbering ABC0001

OSCL two - numbering ABC0001

Next numbering

OSCL - ABC0003

Missing numbering = ABC0002

The query as below:

Declare @fmt_num as Integer

Select @fmt_num=count(OSCL.CallID) from OSCL

SELECT 'ABC'+ replace(str((@fmt_num)+1,7,0),' ',0)

Can anyone help to refine the query or there is others way.