Suppose I have a table with a colour field — red/white/blue — and every time my app receives an event over TCP/IP and inserts a new row into the database, I want a data-aware pie chart component to auto-update showing the ratio of those colours. How can I do that?
I've seen examples of data-aware components, but they just show the value of each row of a table (I haven't gotten too far yet). In fact, I am not even sure that adding another row in the database will add another row to the DB-aware grid (push, as opposed to pull).
I am not even sure that adding another row in the database will add another row to the DB aware grid (push, as opposed to pull).
If the dataset is live
, adding a row to the dataset will update the grid.
Look, let's just imagine that I have a table who's primary key is a colour - red/white/blue - and every time my app receives an event over TCP/IP and inserts a new row into the database I want a data-aware pie chart component to auto-update showing the ratio of those colours.
Connection
to your form, set it up so it connects to your database. connection
active
property to true
connection1
sql
property to SELECT (count(*) / b.totalcount) as percentage, b.totalcount FROM table1 a CROSS JOIN (select count(*) as totalcount from table1) b GROUP BY a.color
active
property to true
datasource
on the form, set its dataset
to query1
datasource
to datasource1