Now, the number of rows in 'Data' sheet is 3938, so the function is:
=SUMPRODUCT((Data!G2:G3938=7100)*(Data!B2:B3938=1000)*(Data!O2:O3938=2)*(Data!C2:C3938))

If I don't know the number of rows is 3938, what should I do to accomplish the same function.