Bapis are remote enabled function modules.Bapi fm are stored in R/3.My question is, Using them,
1. can we get data from legacy system and
2. can we send data from R/3.
Yes. We can get the Data from Legacy System using BAPIs. In some of the scenarios, we may need information for our R/3 System from the Legacy System which contains data relevant for R/3 Transactions. So, by using BAPI calls, we can get the Data from the Legacy Systems. The Key is that the Legacy / Remote System should be able to respond to our BAPI Calls.
Coming to your second question, we can send data to Legacy System in various forms using BAPI calls.
For example, I have worked on a Scenario where the Customer enters the Customer Number, Order Number, PO Number & the Date Range on a Web Site and Clicks on Submit button to Check the Status of all the Orders he placed. Now, internally, the Java Script / VB Script code written at the Web Services call the BAPI which I've developed in the R/3 System.
And this BAPI fetches all the data from Sales Order Header / Item & Business as well as the Status Tables and sends the data back to the Customer's Web Site.
Hope the explanation was clear.
Thanks and Regards,
Venkat Phani Prasad Konduri