readonly grid

Question

Hi All, 
 I have user interface with a read only grid and a button called "ASSIGN" to each row. 
 When the user clicks on any of the button "ASSIGN" then for the respective record I have to update few columns again the selected database record. 
 When I try to use a process model with a "Write to Data Store Entity" then it is making NULL to all of other column value except which I have try to pass. 
 How can I update the specific column value when the user clicks on the "ASSIGN" button without touching all other column/field values in the database.

Mike Schmitt · Answer

In the process model, simply query the latest value of that row into your PV, then update the value in the specific column(s) desired, then write the new value back to the DB in a WTDS node. This is pretty straight forward.

Mike Schmitt · Answer

Hari Kishore Reddy said: do I need to use "Query Database Smart Service" 
 No - best practices are to avoid that node at all costs unless strictly required (which in most normal cases, it won't be). To query the value of a row of a table, you merely need to use a Query Entity in the data output of a node such as a Script Task. 
 I recommend having an expression rule pre-defined to allow you to easily query the DSE associated to different CDTs you'll be using commonly in your application, as this dramatically simplifies the process of arbitrarily adding a Query Entity call in different places like process nodes, interfaces, etc.