IF EXISTS(SELECT 1 FROM TABLE_NAME WHERE COL_A = ? AND COL_B = ? AND COL_C = ?)
BEGIN
UPDATE TABLE_NAME
SET COL_D = ? COL_E = ?
WHERE COL_A = ? AND COL_B = ? AND COL_C = ? AND COL_C > 15
END
ELSE
BEGIN
INSERT INTO TABLE_NAME
(COL_A, COL_B, COL_C, COL_D, COL_E)
VALUES
(?, ?, ?, ?, ?)
END