SQL Server INSERT INTO with WHERE clause

Question

I\'m trying to insert some mock payment info into a dev database with this query:

INSERT
    INTO
        Payments(Amount)
    VALUES(12.33)
WHERE
    Paymen         


        

Answer 1

Better solution and without risk of deadlocks:

UPDATE Payments
    SET Amount = 12.33
WHERE CustomerID = '145300'

INSERT INTO Payments(CustomerID,Amount)
    SELECT '145300',12.33
WHERE @@ROWCOUNT=0