You don't provide enough context for me to answer your question simply.
If the code that you posted runs in a DB2 context (probably vla a linked query), then it is fine as you wrote it. An example would be:
If you have already copied rows to a scratch OrderDetail table on SQL Server and need to extract only the current day's data, then there are a couple of choices based on the datatype you picked for the invDate column. The universal solution would be:
INSERT INTO SQLServerTable (orderID, invDate, OrderAmount)
SELECT orderID, invDate, OrderAmount
FROM OpenQuery(DB2, 'SELECT orderID, invDate, OrderAmount
WHERE invDate = Current(Date);') AS DB2Query
This is a bit convoluted, but it works on all of the DATE datatypes.
INSERT INTO SQLTable (orderID, invDate, OrderAmt)
SELECT orderID, invDate, OrderAmt
WHERE DateAdd(day, DateDiff(day, GetDate(), 0), 0) <= invDate
AND invDate < DateAdd(day, DateDiff(day, GetDate(), 0), 1);
In theory, theory and practice are identical. In practice, theory and practice are unrelated.